Friederichs, H. F. (1969). How to find my German ancestors and relatives. Degener.
Lua i Stíl Chicago (17ú heag.)Friederichs, Heinz Friedrich. How to Find My German Ancestors and Relatives. Neustadt an der Aisch: Degener, 1969.
Lua MLA (8ú heag.)Friederichs, Heinz Friedrich. How to Find My German Ancestors and Relatives. Degener, 1969.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.