edited by John F. Kantner, Lee McCaffrey
Lexington Books, 1975
Buku Referensi
Barclan, George W., author
Princeton University Press, 1954
Buku Teks
American Society for Training and Development Research
American Society for Training & Development, 2010
eBooks
D. Reidel Publishing Company, 1985
Buku Teks
Development Cooperation Information Department , 1994
Buku Teks