[
  {
    "id": "versailles",
    "title": "Treaty of Versailles, Article 88 and Annex; editorial notes in FRUS",
    "author": "Allied and Associated Powers; US Department of State editors",
    "institution": "Office of the Historian, US Department of State",
    "date": "1919 (treaty); 1947 (FRUS volume)",
    "url": "https://history.state.gov/historicaldocuments/frus1919Parisv13/ch12subch8",
    "catalogId": "FRUS, Paris Peace Conference, vol. XIII, pp. 212–219",
    "language": "en",
    "type": "primary-with-editorial-notes",
    "accessDate": "2026-10-05",
    "reliabilityNotes": {
      "pl": "Traktat jest podstawą reguł plebiscytu. Późniejsze przypisy redakcyjne należy odróżniać od tekstu z 1919 r.",
      "en": "The treaty establishes the plebiscite rules. Later editorial notes must be distinguished from the 1919 text."
    },
    "license": "US government publication; treaty text public domain"
  },
  {
    "id": "first",
    "title": "I powstanie śląskie (1919 r.) – okoliczności wybuchu",
    "author": "Mirosław Węcki",
    "institution": "IPN / Przystanek Historia",
    "date": "2020-08-16",
    "url": "https://przystanekhistoria.pl/pa2/teksty/72210,I-powstanie-slaskie-1919-r-okolicznosci-wybuchu.html",
    "catalogId": null,
    "language": "pl",
    "type": "institutional-history",
    "accessDate": "2026-10-05",
    "reliabilityNotes": {
      "pl": "Synteza historyka IPN. Daty ostatnich starć odróżniane od rozkazu zakończenia walk. Szacunków ofiar nie traktujemy jako pełnego rejestru.",
      "en": "An IPN historian’s synthesis. Last clashes are distinguished from the order to stop fighting. Casualty estimates are not a complete register."
    },
    "license": "Text consulted for factual research; no reproduction permission assumed"
  },
  {
    "id": "miners",
    "title": "„Przybyli po wypłatę górnicy”",
    "author": "Sebastian Rosenbaum",
    "institution": "IPN / Przystanek Historia",
    "date": "2021",
    "url": "https://przystanekhistoria.pl/pa2/tematy/powstania-slaskie/81122,Przybyli-po-wyplate-gornicy.html",
    "catalogId": null,
    "language": "pl",
    "type": "institutional-history",
    "accessDate": "2026-10-05",
    "reliabilityNotes": {
      "pl": "Analiza strajku i relacji prasowych; istotna dla krytyki opowieści o jednej przyczynie powstania.",
      "en": "Analysis of the strike and newspaper accounts; useful for testing single-cause narratives."
    },
    "license": "Text consulted for factual research; no reproduction permission assumed"
  },
  {
    "id": "second",
    "title": "II Powstanie Śląskie",
    "author": "Mirosław Węcki",
    "institution": "Instytut Pamięci Narodowej",
    "date": "2025-08-19",
    "url": "https://ipn.gov.pl/pl/historia-z-ipn/227759,II-Powstanie-Slaskie.html",
    "catalogId": null,
    "language": "pl",
    "type": "institutional-history",
    "accessDate": "2026-10-05",
    "reliabilityNotes": {
      "pl": "Opis zawiera działania od 18 sierpnia i końcowe starcia do 28 sierpnia; standardowy zakres 19/20–25 sierpnia nie wyczerpuje wszystkich działań.",
      "en": "The account includes actions from 18 August and final fighting through 28 August; the conventional 19/20–25 August range does not cover every action."
    },
    "license": "Text consulted for factual research; no reproduction permission assumed"
  },
  {
    "id": "third",
    "title": "Plebiscyt i III Powstanie Śląskie 1921 roku",
    "author": "Mirosław Węcki",
    "institution": "IPN / Przystanek Historia",
    "date": "2021-05-03",
    "url": "https://przystanekhistoria.pl/pa2/teksty/91529,Plebiscyt-i-III-Powstanie-Slaskie-1921-roku.html",
    "catalogId": null,
    "language": "pl",
    "type": "institutional-history",
    "accessDate": "2026-10-05",
    "reliabilityNotes": {
      "pl": "Szczegółowa chronologia wojskowa i polityczna. Sumy plebiscytu różnią się od innego tekstu IPN; nie łączymy zbiorów.",
      "en": "Detailed military and political chronology. Plebiscite totals differ from another IPN article; datasets are not combined."
    },
    "license": "Text consulted for factual research; no reproduction permission assumed"
  },
  {
    "id": "vote",
    "title": "The Upper Silesian plebiscite of 20 March 1921 – the course of voting",
    "author": null,
    "institution": "Institute of National Remembrance",
    "date": "2022-01-11",
    "url": "https://eng.ipn.gov.pl/en/digital-resources/articles/9176,The-Upper-Silesian-plebiscite-of-20-March-1921-the-course-of-voting.html",
    "catalogId": null,
    "language": "en",
    "type": "institutional-history",
    "accessDate": "2026-10-05",
    "reliabilityNotes": {
      "pl": "Źródło wybranego zestawu liczb: 479365 i 707393. Publikowane procenty mają różne mianowniki; wykres obliczamy z dwóch opcji.",
      "en": "Source of the selected totals: 479365 and 707393. Published percentages use differing denominators; the chart is calculated from the two options."
    },
    "license": "Text consulted for factual research; no reproduction permission assumed"
  },
  {
    "id": "partition-plans",
    "title": "Ideas for the Division of Upper Silesia After the Plebiscite",
    "author": "Renata Skoczek",
    "institution": "Institute of National Remembrance",
    "date": "2021-05-07",
    "url": "https://eng.ipn.gov.pl/en/digital-resources/articles/8108,Ideas-for-the-Division-of-Upper-Silesia-After-the-Plebiscite.html",
    "catalogId": null,
    "language": "en",
    "type": "institutional-history",
    "accessDate": "2026-10-05",
    "reliabilityNotes": {
      "pl": "Propozycje podziału nie są ostateczną granicą. Wypowiedzi Korfantego są stanowiskiem politycznym.",
      "en": "Partition proposals are not the final border. Korfanty’s statements represent a political position."
    },
    "license": "Text consulted for factual research; no reproduction permission assumed"
  },
  {
    "id": "fic",
    "title": "Upper Silesia plebiscite – an intensive course in Polish identity",
    "author": "University editorial interview with Maciej Fic",
    "institution": "University of Silesia",
    "date": "2021-03-19",
    "url": "https://us.edu.pl/en/plebiscyt-na-gornym-slasku-przyspieszony-kurs-polskosci/",
    "catalogId": null,
    "language": "en",
    "type": "scholarly-interview",
    "accessDate": "2026-10-05",
    "reliabilityNotes": {
      "pl": "Wywiad z badaczem. Nie utożsamia języka domowego z deklaracją narodową. Dane przemysłowe dotyczą konkretnych kategorii, nie całej gospodarki.",
      "en": "Interview with a researcher. Household language is not equated with nationality. Industrial counts concern specific categories, not the whole economy."
    },
    "license": "Text consulted for factual research; no reproduction permission assumed"
  },
  {
    "id": "identity",
    "title": "Celebrating the nation: the case of Upper Silesia after the plebiscite in 1921",
    "author": "Andrzej Michalczyk",
    "institution": "UCL Discovery (research repository)",
    "date": null,
    "url": "https://discovery.ucl.ac.uk/16348/1/16348.pdf",
    "catalogId": null,
    "language": "en",
    "type": "scholarly-paper",
    "accessDate": "2026-10-05",
    "reliabilityNotes": {
      "pl": "Autor potwierdzony na s. 49 PDF; wykorzystane s. 50–51 o języku, religii i identyfikacji regionalnej.",
      "en": "Author confirmed on PDF p. 49; pp. 50–51 used on language, religion and regional identification."
    },
    "license": "Text consulted for factual research; no reproduction permission assumed"
  },
  {
    "id": "dhm",
    "title": "Die Teilung Oberschlesiens",
    "author": "Arnulf Scriba",
    "institution": "Deutsches Historisches Museum / LeMO",
    "date": "2014-09-02",
    "url": "https://www.dhm.de/lemo/kapitel/weimarer-republik/aussenpolitik/teilung-oberschlesiens-1921",
    "catalogId": null,
    "language": "de",
    "type": "museum-history",
    "accessDate": "2026-10-05",
    "reliabilityNotes": {
      "pl": "Niemiecka narracja muzealna. Data 23 maja dla Annaberg różni się od 21 maja w szczegółowej chronologii IPN. Oceny podziału są interpretacją.",
      "en": "German museum narrative. Its Annaberg date of 23 May differs from 21 May in the detailed IPN chronology. Assessments of partition are interpretations."
    },
    "license": "CC BY-NC-SA 4.0 for text per page; images separately restricted. Facts paraphrased, no image reused"
  },
  {
    "id": "settlement",
    "title": "Powstania śląskie 1919–1921: exhibition leaflet",
    "author": null,
    "institution": "Instytut Pamięci Narodowej",
    "date": "2021",
    "url": "https://ipn.gov.pl/download/81/577118/ulotka792x210DRUK21.pdf",
    "catalogId": null,
    "language": "pl",
    "type": "educational-exhibition",
    "accessDate": "2026-10-05",
    "reliabilityNotes": {
      "pl": "Materiały edukacyjne. Wykorzystana strona 2: rozejm, podział i objęcie regionu. Prawa do zdjęć nie wynikają z dostępu do PDF.",
      "en": "Educational material. Page 2 used for ceasefire, partition and transfer. Access to the PDF does not establish rights to its images."
    },
    "license": "Text consulted for factual research; no reproduction permission assumed"
  },
  {
    "id": "monument",
    "title": "Jak powstawał Pomnik Powstańców Śląskich w Katowicach, 1965–1967",
    "author": "Joanna Sowa; Przemysław Snoch",
    "institution": "Archiwum Państwowe w Katowicach",
    "date": "2021",
    "url": "https://katowice.ap.gov.pl/ap/tekst/jak-powstawa-pomnik-powstacow-lskich-w-katowicach-1965-1967",
    "catalogId": "AP Katowice, fonds 12/274 (exhibition reference; no invented item number)",
    "language": "pl",
    "type": "archival-exhibition",
    "accessDate": "2026-10-05",
    "reliabilityNotes": {
      "pl": "Wystawa oparta na zasobie archiwum; dokumentuje konkurs, autorstwo, materiał, daty i symbolikę.",
      "en": "Exhibition based on archival holdings; documents competition, authorship, material, dates and symbolism."
    },
    "license": "Text consulted for factual research; no reproduction permission assumed"
  },
  {
    "id": "monument-city",
    "title": "Uchwała Nr IV/47/24 Rady Miasta Katowice",
    "author": "Rada Miasta Katowice",
    "institution": "BIP Katowice",
    "date": "2024-06-20",
    "url": "https://bip.katowice.eu/Lists/Dokumenty/Attachments/141339/SESJA%20IV-47-24.pdf",
    "catalogId": "IV/47/24",
    "language": "pl",
    "type": "official-document",
    "accessDate": "2026-10-05",
    "reliabilityNotes": {
      "pl": "Dokumentuje nazwę i wpis do rejestru zabytków A/1348/24 z 19 lutego 2024 r.",
      "en": "Documents the official name and heritage listing A/1348/24, dated 19 February 2024."
    },
    "license": "Polish official document"
  },
  {
    "id": "korfanty",
    "title": "Ślązak i Polak Wojciech Korfanty (1873–1939)",
    "author": "Sebastian Rosenbaum; Mirosław Węcki",
    "institution": "Instytut Pamięci Narodowej",
    "date": "2026-04-20",
    "url": "https://ipn.gov.pl/pl/historia-z-ipn/169042,sebastian-rosenbaum-miroslaw-wecki-slazak-i-polak-wojciech-korfanty-18731939.html",
    "catalogId": null,
    "language": "pl",
    "type": "institutional-biography",
    "accessDate": "2026-10-05",
    "reliabilityNotes": {
      "pl": "Weryfikacja pochodzenia, edukacji i kariery. Fragment odsyła do pełnego tekstu.",
      "en": "Verification of background, education and career. Excerpt links to full article."
    },
    "license": "Text consulted for factual research; no reproduction permission assumed"
  },
  {
    "id": "zgrzebniok",
    "title": "Alfons Zgrzebniok",
    "author": "Witold Iwaszkiewicz",
    "institution": "Instytut Pamięci Narodowej",
    "date": "2021",
    "url": "https://ipn.gov.pl/download/1/614305/BohaterowieniepodleglejAlfonsZgrzebniokzabezpieczony.pdf",
    "catalogId": null,
    "language": "pl",
    "type": "institutional-biography",
    "accessDate": "2026-10-05",
    "reliabilityNotes": {
      "pl": "Biografia instytucjonalna; wykorzystanie podstawowych dat i roli dowódczej.",
      "en": "Institutional biography; basic dates and command role consulted."
    },
    "license": "Text consulted for factual research; no reproduction permission assumed"
  },
  {
    "id": "database",
    "title": "Powstańcy Śląscy",
    "author": null,
    "institution": "Archiwa Państwowe",
    "date": null,
    "url": "https://archiwa.gov.pl/portale-tematyczne/powstancy-slascy/",
    "catalogId": null,
    "language": "pl",
    "type": "official-archive-guide",
    "accessDate": "2026-10-05",
    "reliabilityNotes": {
      "pl": "Instytucja potwierdza oficjalną bazę Znajdź powstańca. Brak ustalonej otwartej licencji eksportu; żadnych rekordów nie skopiowano.",
      "en": "Institution confirms the official Find an Insurgent database. No open export licence established; no records copied."
    },
    "license": "Text consulted for factual research; no reproduction permission assumed"
  },
  {
    "id": "archives",
    "title": "Zbiory online",
    "author": null,
    "institution": "Archiwum Państwowe w Katowicach",
    "date": null,
    "url": "https://www.katowice.ap.gov.pl/ap/online",
    "catalogId": null,
    "language": "pl",
    "type": "official-archive-guide",
    "accessDate": "2026-10-05",
    "reliabilityNotes": {
      "pl": "Kieruje do oficjalnych zasobów cyfrowych. Dostęp nie oznacza automatycznej licencji.",
      "en": "Links to official digital holdings. Access does not automatically establish a reuse licence."
    },
    "license": "Text consulted for factual research; no reproduction permission assumed"
  },
  {
    "id": "casualty-research",
    "title": "Program badawczy: polegli w powstaniach śląskich",
    "author": "Edward Długajczyk",
    "institution": "Archiwum Państwowe w Katowicach / Szkice Archiwalno-Historyczne nr 20",
    "date": "2023",
    "url": "https://katowice.ap.gov.pl/szkice20_2023/dlugajczyk_program_badawczy_polegli_w_powstaniach_slaskich.pdf",
    "catalogId": "DOI 10.61516/szkice20_2023/dlugajczyk",
    "language": "pl",
    "type": "research-paper",
    "accessDate": "2026-10-05",
    "reliabilityNotes": {
      "pl": "Program badawczy wskazuje potrzebę identyfikacji imiennej; użyty jako wskazówka dalszych badań, nie źródło gotowej liczby ofiar.",
      "en": "Research programme points to the need for identification by name; used as a research lead, not as a completed casualty count."
    },
    "license": "Text consulted for factual research; no reproduction permission assumed"
  },
  {
    "id": "korfanty-full",
    "title": "Ślązak i Polak Wojciech Korfanty (1873–1939)",
    "author": "Sebastian Rosenbaum; Mirosław Węcki",
    "institution": "IPN / Przystanek Historia",
    "date": "2022-08-16",
    "url": "https://przystanekhistoria.pl/pa2/teksty/43453,Slazak-i-Polak-Wojciech-Korfanty-18731939.html",
    "catalogId": null,
    "language": "pl",
    "type": "institutional-biography",
    "accessDate": "2026-10-05",
    "reliabilityNotes": {
      "pl": "Pełna biografia. Daty i role porównane z chronologią powstania; interpretacje polityczne są oceną autorów.",
      "en": "Full biography. Dates and roles compared with the uprising chronology; political assessments are the authors’ interpretations."
    },
    "license": "Consulted, not reproduced"
  },
  {
    "id": "geonames",
    "title": "GeoNames geographical database: Poland extract",
    "author": "GeoNames contributors",
    "institution": "GeoNames",
    "date": "2026-10-05 (download)",
    "url": "https://download.geonames.org/export/dump/",
    "catalogId": "PL.zip; individual IDs in place records",
    "language": "mul",
    "type": "modern-gazetteer",
    "accessDate": "2026-10-05",
    "reliabilityNotes": {
      "pl": "Współczesne punkty miejscowości WGS84. Nie wyznaczają granic historycznych ani dokładnych stanowisk walk.",
      "en": "Modern WGS84 settlement points. They do not establish historical borders or exact battle positions."
    },
    "license": "CC BY 4.0; https://creativecommons.org/licenses/by/4.0/"
  },
  {
    "id": "zenkteler",
    "title": "Kazimierz Zenkteler „Warwas”",
    "author": null,
    "institution": "Instytut Pamięci Narodowej / Biogramy",
    "date": null,
    "url": "https://biogramy.ipn.gov.pl/bio/wszystkie-biogramy/110537,Kazimierz-Zenkteler-Warwas.html",
    "catalogId": null,
    "language": "pl",
    "type": "institutional-biography",
    "accessDate": "2026-10-05",
    "reliabilityNotes": {
      "pl": "Biogram instytucjonalny służy do sprawdzenia nazwiska i następstwa dowództwa. Nie przejmujemy rocznicowej oceny wartościującej.",
      "en": "Institutional biography used to verify the name and command succession. Its commemorative value judgments are not adopted."
    },
    "license": "Consulted, not reproduced"
  }
]