The field of 61 Cygni ;
A study of Yerkes observatory parallax photographs,
by Mary Murray Hopkins...
APA Citation
Hopkins, M. Murray. (1915). The field of 61 Cygni: A study of Yerkes observatory parallax photographs. New York.
MLA Citation
Hopkins, Mary Murray, b. 1878. The Field of 61 Cygni: A Study of Yerkes Observatory Parallax Photographs. New York, 1915.
Warning: These citations may not always be complete (especially for serials).