APA (7th ed.) Zitazioa

PENNEY, D. E. (1972). Perspectives in mathematics. Benjamin.

Chicago Style (17th ed.) Zitazioa

PENNEY, David E. Perspectives in Mathematics. California: Benjamin, 1972.

MLA (9th ed.) Zitazioa

PENNEY, David E. Perspectives in Mathematics. Benjamin, 1972.