Gaya APA

VERSTAPPEN, H, T. (1973). A GEOMORPHOLOGICAL RECONNAISSSANCE OF SUMATRA AND ADJACENT ISLANOS . Amsterdam: INTERNATIONAL INSTITUTE FOR AERIAL SURVEY.

Gaya MLA

VERSTAPPEN, H., TH.. "A GEOMORPHOLOGICAL RECONNAISSSANCE OF SUMATRA AND ADJACENT ISLANOS". Amsterdam: INTERNATIONAL INSTITUTE FOR AERIAL SURVEY, 1973. Textbook.