Scott, Foresman and Co., 1987
Buku Teks
Ritchie, Donald A., author
Macmillan, 1985
Buku Teks
Kennedy, David M., 1905-1996, author
Wadsworth and Cengage Learning, 2012
Buku Teks
Andresen, Tetel Julie, author
Routledge, 1990
Buku Teks
Bedford, Henry F., author
Harcourt Brace Jovanovich, 1972
Buku Teks