Artikel Jurnal
Garton, Jeffrey, author
American Society for Training & Development, 2008
eBooks
Wilmot, Chester, author
ST. James`s Place, 1952
Buku Teks
Meuthia Ganie Rochman, author
Fakultas Ilmu Sosial dan Ilmu Politik Universitas Indonesia, 2002
Buku Teks
Soetan Sjahrir, 1909-1966, author
Southeast Asia Program Cornell University, 1968
Buku Teks