APA (7th ed.) Citation

B. Klein & Company & Klein, B. (1960). Guide to American directories. B. Klein and Company.

Chicago Style (17th ed.) Citation

B. Klein & Company and Bernard Klein. Guide to American Directories. New York: B. Klein and Company, 1960.

MLA (9th ed.) Citation

B. Klein & Company and Bernard Klein. Guide to American Directories. B. Klein and Company, 1960.