Field, John, author
Routledge, 2005
Buku Teks
Steinberg, Danny D., author
Longman, 1982
Buku Teks
Malmstrom, Jean, author
Hayden Book Company, 1965
Buku Teks
Bram, Joseph, author
Random House, 1955
Buku Teks
Downes, William, author
Cambridge University Press, 2003
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