Landy, Frank J., author
Wiley, 2013
Buku Teks
edited by P.J.D. Drenth ... [and others]
John Wiley & Sons, 1984
Buku Referensi
Auerbach Alan J., author
Brown & Benchmark, 1996
Buku Teks
Fletcher, Ronald, 1921-, author
George Allen and Unwin , 1957
Buku Teks
Watson, Tony J., author
Prentice-Hall, 2002
Buku Teks