APA (7th ed.) Citation

Hirshberg, H. S. (1942). Subject guide to reference books. American library association.

Chicago Style (17th ed.) Citation

Hirshberg, Herbert S. Subject Guide to Reference Books. Chicago: American library association, 1942.

MLA (9th ed.) Citation

Hirshberg, Herbert S. Subject Guide to Reference Books. American library association, 1942.

Warning: These citations may not always be 100% accurate.