Cummings, Milton C.
Harcourt Brace Jovanovich, 1981
Buku Teks
Cummings, Milton C.
Harcourt Brace Jovanovich, 1977
Buku Teks
Geer, John Gray
Wadsworth and Cengage Learning, 2012
Buku Teks
by John G. Geer [and others]
Wadsworth and Cengage Learning, 2012
Buku Teks
Dye, Thomas R., author
Harcourt Brace College, 2000
Buku Teks