Variable stars,
by Cecilia Payne-Gaposchkin and Sergei Gaposchkin ...
APA Citation
Gaposchkin, C. Helena Payne., Gaposchkin, S. (1938). Variable stars. Cambridge, Mass.: The Observatory.
MLA Citation
Gaposchkin, Cecilia Helena Payne, 1900-, and Sergei Gaposchkin. Variable Stars. Cambridge, Mass.: The Observatory, 1938.
Warning: These citations may not always be complete (especially for serials).