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Edward Elgar, 2013
Buku Teks
Sundararajan, V.
Tata McGraw-Hill, 1982
Buku Teks
Porterfield, John D.
Voice American Forum Lecture, [date of publication not identified]
Buku Teks
D. Subagio
Novindo Pustaka Mandiri, 1996
Buku Teks
[publisher not identified], [date of publication not identified]
Naskah