Cambridge University Press, 2004
eBooks
Pillar, Paul R.
Princeton University Press , 1983
Buku Teks
Annual Review, INC, 1964
Buku Teks
Johnson, Clive, 1930-, compiler
Bantam Books, 1971
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Perkins, John
Berrett-Koehler Publishers, 2016
Buku Teks