O`Hair, Dan, author
Allyn and Bacon, 2011
Buku Teks
Phillips, Gerald M., author
Macmillan, 1982
Buku Teks
Munter, Mary, author
Prentice-Hall, 1982
Buku Referensi
Prescott, David
Harcourt Brace Jovanovich, 1993
Buku Teks
O`Hair, Dan, author
Allyn and Bacon, 2011
Buku Teks