Payne, Richard J., 1949-, author
Pearson Education , 2014
Buku Teks
edited by Oscar Uribe-Villegas
Mouton, 1977
Buku Teks
Novak, Mark, author
Pearson, 2014
Buku Teks
Novak, Mark, author
Pearson, 2014
Buku Teks
Numrich, Carol, author
Longman: Addison-Wesley Pub., 1995
Buku Referensi