Unknown. (1931). Letter in German, February 9, 1931. Saint Louis University Libraries Digitization Center.
Chicago Style (17th ed.) CitationUnknown. Letter in German, February 9, 1931. Saint Louis University Libraries Digitization Center, 1931.
MLA (8th ed.) CitationUnknown. Letter in German, February 9, 1931. Saint Louis University Libraries Digitization Center, 1931.
Warning: These citations may not always be 100% accurate.