Page one publishing pte ltd, 2011
Buku Referensi
Roojen, Pepin van, compiler
Pepin Press, 2010
Multimedia
Rockport publishers, Inc.;, 2011
Buku Referensi
Fladager, Vernon L.
McGraw-Hill , 1956
Buku Teks
Friedman, Walter F.
John Wiley & Sons, 1960
Buku Teks