APA

(2006). Twentieth Century Views. A Spectrum Book. Englewood Cliffs: Prentice-Hall.

Chicago

2006. Twentieth Century Views. A Spectrum Book. Englewood Cliffs: Prentice-Hall.

Harvard

(2006). Twentieth Century Views. A Spectrum Book. Englewood Cliffs: Prentice-Hall.

MLA

Twentieth Century Views. A Spectrum Book. Englewood Cliffs: Prentice-Hall. 2006.