Krapp, K. M. (1998). Notable twentieth-century scientists: Supplement. Gale Research.
Lua i Stíl Chicago (17ú heag.)Krapp, Kristine M. Notable Twentieth-century Scientists: Supplement. Detroit: Gale Research, 1998.
Lua MLA (9ú heag.)Krapp, Kristine M. Notable Twentieth-century Scientists: Supplement. Gale Research, 1998.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.