Rossman, Allan J., author
Key College, 2001
Buku Teks
Robert, Harry V., author
McGraw-Hill, 1982
Buku Teks
Noggle, Joseph H.
Ellis Horwood, 1993
Buku Teks
Kozelka, Robert M., author
Addison-Wesley, 1961
Buku Teks
Winkler, Robert L., author
Holt, Rinehart and Winston, 1975
Buku Teks