Soudagar, Reza, author
McGraw-Hill, 2012
Buku Teks
Davis, Ray
Lycos Press,, 1997
Buku Referensi
Ormrod, Jeanne Ellis, author
Pearson, 2020
Buku Teks
Ormrod, Jeanne Ellis, author
Prentice-Hall, 2003
Buku Teks
Ormrod, Jeanne Ellis, author
Charles E. Merrill, 2000
Buku Teks