Springer, 2012
eBooks
Olga Aikin
IPM, 1994
Buku Teks
Clarke, Linda, author
Institute of Personnel and Development, 1993
Buku Teks
Meier, Gerald M., author
Oxford University Press, 1979
Buku Teks
Nash, Bradley D
Center for the study of the Presidency, 1980
Buku Teks