Cambridge University Press, 2005
eBooks
Wilson, Frank W., editor-in-cheif
McGraw-Hill, 1963
Buku Referensi
Parris, Melanie
McGraw-Hill, 2012
Buku Teks
Cambridge University Press, 2008
eBooks
Bowden, Edwin T.
Holt, Rinehart and Winston, 1963
Buku Teks