Wagner, G. A. (1934). Letter to Ravenna Mosaic Company, May 17, 1934. Saint Louis University Libraries Digitization Center.
Chicago-viite (17. p.)Wagner, Gerdt A. Letter to Ravenna Mosaic Company, May 17, 1934. Saint Louis University Libraries Digitization Center, 1934.
MLA-viite (8. p.)Wagner, Gerdt A. Letter to Ravenna Mosaic Company, May 17, 1934. Saint Louis University Libraries Digitization Center, 1934.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.