John Wiley & Sons , 2009
Buku Teks
Sage Publications, 2009
eBooks
edited by Shirley Fisher and James Reason
John Wiley & Sons, 1988
Buku Referensi
edited by Cary L. Cooper, James Campbell Quick, Marc J. Schabracq
John Wiley & Sons, 2009
Buku Teks
World Vision, 2003
Buku Teks