Pinet, Paul R.
Jones and Bartlett Publishers, 1998
Buku Teks
Garrison, Tom, 1942-, author
National Geographic Learning/Cengage Learning, 2016
Buku Teks
Yasso, Warren E.
New York: Holt, Rinehart and Winston, 1965
Buku Teks
Yasso, Warren E.
New York: Holt, Rinehart and Winston, 1965
Buku Teks
Anderson, Franz E., author
Burgess Publishing, 1979
Buku Teks