Nina Rovinelli Heller, Alex Gitterman, editor
Routledge, 2011
Buku Teks
Smith, Michael J., author
Oxford University Press, 2010
Buku Teks
edited by Bruce A. Thyer and John S. Wodarski
John Wiley, 2007
Buku Teks
Rosskam, E.
International Labour Office, 1996
Buku Teks
The Haworth Press, 1984
Buku Teks