Gaya APA
Soil Science Simplified. (1980).
Iowa:
IOWA State University.
Gaya Chicago
Soil Science Simplified.
.
Iowa:
IOWA State University,
1980.
Buku.
Gaya MLA
Soil Science Simplified.
.
Iowa:
IOWA State University,
1980.
Buku.
Gaya Turabian
Soil Science Simplified.
Iowa:
IOWA State University,
1980.
Buku.