Movnin, M.
Moscow: Mir Publishers, 1975
Buku Teks
Spotts, Merhyle Franklin
Prentice-Hall, 1998
Multimedia
Wilson, Charles E.
Prentice-Hall, 1997
Buku Teks
Spotts, Merhyle Franklin
Prentice-Hall, 1985
Buku Teks
Jain, Rajendra K.
Khanna Publishers, 1983
Buku Teks