Gaya APA
Investigating the Earth. (1967).
Boston:
Houghton Mifflin Company.
Gaya Chicago
Investigating the Earth.
cet.1.
Boston:
Houghton Mifflin Company,
1967.
.
Gaya MLA
Investigating the Earth.
cet.1.
Boston:
Houghton Mifflin Company,
1967.
.
Gaya Turabian
Investigating the Earth.
Boston:
Houghton Mifflin Company,
1967.
.