Percerou, J.
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Buku Teks
Comer, Ronald J.
New York W.H. Freeman and Co. 1998,
Buku Teks
Compesi, Ronald J.
Allyn and Bacon, 1994
Buku Teks
Busyra Azheri
RajaGrafindo Persada, 2012
Buku Teks
Tocci, Ronald J.
Prentice-Hall, 1985
Buku Teks