Bianki, V.
Foreign Languages Publishing, [Date of publication not identified]
Buku Teks SO
Wallwork, Adrian
Springer, 2010
Buku Teks SO
Morrisey, George L.
Addison-Wesley, 1987
Buku Teks SO
Lindstrom, Robert L.
McGraw-Hill, 1994
Buku Teks SO
Emmerson, Paul
Cambridge University Press, 2005
Buku Teks SO