Não informado. (1935). Contributions from the Perkins Observatory. Ohio State University, Ohio Wesleyan University.
Chicago-Zitierstil (17. Ausg.)Não informado. Contributions from the Perkins Observatory. Delaware, Ohio: Ohio State University, Ohio Wesleyan University, 1935.
MLA-Zitierstil (8. Ausg.)Não informado. Contributions from the Perkins Observatory. Ohio State University, Ohio Wesleyan University, 1935.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.