Heuduck, P. (1946). Letter to Mortimer Schwager, July 1, 1946. Saint Louis University Libraries Digitization Center.
Čikaški stil citiranja (17. izdanje)Heuduck, Paul. Letter to Mortimer Schwager, July 1, 1946. Saint Louis University Libraries Digitization Center, 1946.
MLA način citiranja (8. izdanje)Heuduck, Paul. Letter to Mortimer Schwager, July 1, 1946. Saint Louis University Libraries Digitization Center, 1946.
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