Emerald Publishing Limited, 2019
eBooks
Birley, Sue, author
Financial Times Prentice Hall, 2000
Buku Teks
J. Winardi, author
Kencana Prenada Media, 2004
Buku Teks
J. Winardi, author
Kencana Prenada Media, 2015
Buku Teks
edited by Calvin A. Kent, Donald L. Sexton and Karl H. Vesper
Prentice Hall, 1982
Buku Referensi