MLA

Baumgartner, Leona, 1902-1991. Leona Baumgartner. approximately 1930. https://collections.library.yale.edu/catalog/16787364.

APA, 6th edition

Baumgartner, Leona, 1902-1991. (approximately 1930)[Leona Baumgartner]. https://collections.library.yale.edu/catalog/16787364.