Pena, William M.
John Wiley & Sons, 2012
Buku Teks SO
Davidson, Peter
Academic Group, 1997
Buku Teks SO
IFENGSPACE, 2011
Buku Referensi
edited by Andreas C. Papadakis
VCH Publishers,
Buku Referensi
Muller, Edward J.
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Buku Teks SO