White, Robert W.
Holt, Rinehart and Winston, 1976
Buku Teks
[Springer-Verlag, Springer-Verlag], 2012
eBooks
Bauer, Lauria
London : Routledge, 1998
Buku Teks
Morgan, John, 1944-2004
Oxford University Press, 1990
Buku Teks SO
Nida Fauzia
2018
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