APA
Heintzelman O. H., Heintzelman O. H., .World regional geography. New Delhi: Prentice Hall.
Chicago
Heintzelman Oliver H, Heintzelman Oliver H, .World regional geography. New Delhi: Prentice Hall.
Harvard
Heintzelman O. H., Heintzelman O. H., .World regional geography. New Delhi: Prentice Hall.
MLA
Heintzelman Oliver H, Heintzelman Oliver H, .New Delhi: Prentice Hall. .