APA

Klages K. H. W., . (1949). Ecological Crop Geography. New York: Macmillan Company.

Chicago

Klages Karl H W, . 1949. Ecological Crop Geography. New York: Macmillan Company.

Harvard

Klages K. H. W., . (1949). Ecological Crop Geography. New York: Macmillan Company.

MLA

Klages Karl H W, . Ecological Crop Geography. New York: Macmillan Company. 1949.