APA (7th ed.) Citation

(1951). Directory of American Scholars: A biographical directory (2. ed.). Science Press.

Chicago Style (17th ed.) Citation

Directory of American Scholars: A Biographical Directory. 2. ed. Lancaster, Pa: Science Press, 1951.

MLA (9th ed.) Citation

Directory of American Scholars: A Biographical Directory. 2. ed. Science Press, 1951.