Platt, Jennifer
Cambridge University Press , 1996
Buku Teks
Turner, Jonathan H., author
Thomson, Wadsworth, 2007
Buku Teks
Tindall, George Brown, author
Norton, 1992
Buku Referensi
Brownlee, W. Elliot, 1941-, author
Cambridge University Press, 2016
Buku Teks
Risjord, Norman K., author
Prentice-Hall, 1985
Buku Teks