Gaya APA
Exercises in physical geograhy. (1999).
New York:
McGraw-Hill.
Gaya Chicago
Exercises in physical geograhy.
3rd.
New York:
McGraw-Hill,
1999.
Buku.
Gaya MLA
Exercises in physical geograhy.
3rd.
New York:
McGraw-Hill,
1999.
Buku.
Gaya Turabian
Exercises in physical geograhy.
New York:
McGraw-Hill,
1999.
Buku.