Não informado. (1935). Contributions from the Perkins Observatory. Ohio State University, Ohio Wesleyan University.
Style de citation Chicago (17e éd.)Não informado. Contributions from the Perkins Observatory. Delaware, Ohio: Ohio State University, Ohio Wesleyan University, 1935.
Style de citation MLA (8e éd.)Não informado. Contributions from the Perkins Observatory. Ohio State University, Ohio Wesleyan University, 1935.
Attention : ces citations peuvent ne pas être correctes à 100%.