APA (7th ed.) Zitazioa

Halacy, D. (1968). Century 21 : your life in the year 2001 and: Beyond. Macrae Smith.

Chicago Style (17th ed.) Zitazioa

Halacy, D.S. Century 21 : Your Life in the Year 2001 and: Beyond. Philadelphia: Macrae Smith, 1968.

MLA (9th ed.) Zitazioa

Halacy, D.S. Century 21 : Your Life in the Year 2001 and: Beyond. Macrae Smith, 1968.