APA

Worrall J., Worrall I. J., . (1969). Introduction to valence theory. New York: American Elsevier Pub. Co.

Chicago

Worrall Jean, Worrall I J, . 1969. Introduction to valence theory. New York: American Elsevier Pub. Co.

Harvard

Worrall J., Worrall I. J., . (1969). Introduction to valence theory. New York: American Elsevier Pub. Co.

MLA

Worrall Jean, Worrall I J, . Introduction to valence theory. New York: American Elsevier Pub. Co. 1969.