Greenberg, Florence Bonzer
The Bobbs-Merrill, 1967
Buku Teks SO
Holladay, Sylvia A.
Prentice-Hall, 1981
Buku Teks SO
Corbett, Edward P.J.
Scott, Foresman and Company, 1983
Koleksi Publik
Hirschberg, Stuart
Prentice-Hall, 1997
Buku Teks SO
Flemming, Laraine E.
Hougtton-Mifflin, 1996
Buku Teks SO