Schwager, M. (1947). Letter to Arno Heuduck, December 29, 1947. Saint Louis University Libraries Digitization Center.
Lua i Stíl Chicago (17ú heag.)Schwager, Mortimer. Letter to Arno Heuduck, December 29, 1947. Saint Louis University Libraries Digitization Center, 1947.
Lua MLA (8ú heag.)Schwager, Mortimer. Letter to Arno Heuduck, December 29, 1947. Saint Louis University Libraries Digitization Center, 1947.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.