APA

Hamann O., . (1980). Studier over Galapagosoernes vegetation. : .

Chicago

Hamann O, . 1980. Studier over Galapagosoernes vegetation. : .

Harvard

Hamann O., . (1980). Studier over Galapagosoernes vegetation. : .

MLA

Hamann O, . Studier over Galapagosoernes vegetation. : . 1980.