MLA

Baumgartner, Leona, 1902-1991. Leona Baumgartner. approximately 1956. https://collections.library.yale.edu/catalog/16787366.

APA, 6th edition

Baumgartner, Leona, 1902-1991. (approximately 1956)[Leona Baumgartner]. https://collections.library.yale.edu/catalog/16787366.