Phillips, Gerald M., author
Macmillan, 1982
Buku Teks
Pepper, Gerald L., author
McGraw-Hill, 1995
Buku Teks
Berko, Roy M, author
Houghton Miffiln, 2001
Buku Teks
Hanna, Michael S., 1939-, author
McGraw-Hill, 1991
Buku Teks
Gudykunst, William B
McGraw-Hill, 1992
Buku Teks