Pettinger, Richard, author
Capstone Publishing, 2002
Buku Teks
Pettinger, Richard
Capstone Publishing, 2002
Buku Teks
Phillips,Patricia Pulliam, author
American Society for Training & Development, 2012
eBooks
March, James G., author
Wiley, 1950
Buku Teks
K. G. Saur, 1986
Buku Referensi