Gaya APA
Natural resources: Young geographer. (1993).
New York:
Thomson Learning.
Gaya Chicago
Natural resources: Young geographer.
.
New York:
Thomson Learning,
1993.
Buku.
Gaya MLA
Natural resources: Young geographer.
.
New York:
Thomson Learning,
1993.
Buku.
Gaya Turabian
Natural resources: Young geographer.
New York:
Thomson Learning,
1993.
Buku.