Source

• {#1} Rudolph Kopec’s Certificate of Arrival and Petition for Naturalization (MR15881). Michigan, Eastern and Western Districts, Naturalization Records, 1837-1993 (MR15882); where: petition 155198, filed Sept 24, 1941, granted 773-5248856, certificate 8 213028 Dec 31, 1940; repository: National Archives and Records Administration, where: NAID 1137682 https://catalog.archives.gov/id/1137682
  citation: 16 APR 2023, FamilySearch, DGS 102549271, file 1061, Maciej Róg