Gaya APA
Duckson, Don W.. (1999).
Exercises in Physical Geograhy, Third Edition (3rd Ed.).
USA:
McGrawhill.
Gaya Chicago
Duckson, Don W..
Exercises in Physical Geograhy, Third Edition.
3rd Ed.
USA:
McGrawhill,
1999.
Text.
Gaya MLA
Duckson, Don W..
Exercises in Physical Geograhy, Third Edition.
3rd Ed.
USA:
McGrawhill,
1999.
Text.
Gaya Turabian
Duckson, Don W..
Exercises in Physical Geograhy, Third Edition.
3rd Ed.
USA:
McGrawhill,
1999.
Print.