Gaya APA

Strahler, A, N., Strahler, A, H. (1983). Study guide for modern physical geography (ed.2). United States of America: Milestone.

Gaya MLA

Strahler, Arthur, N.., Strahler, Alan, H.. "Study guide for modern physical geography". ed.2 United States of America: Milestone, 1983. Text.