Dearing,James W.
Routledge, 1995
Buku Teks
Chowdhury, Indira, author
Oxford University Press, 2016
eBooks
Misumi, Jyuji, author
University of Michigan Press, 1985.
Buku Teks
Wilson, E. Bright, author
McGraw-Hill, 1952
Buku Teks
Freedman, Paul, author
Public Affairs Press, 1950
Buku Teks