Jeffrey, Grant R
Harvest House Publishers, 1996
Buku Teks
Fowles, Grant R.
Thomson Brooks/Cole,, 1985
Buku Teks
Fowles, Grant R.
Holt, Rinehart, and Winston, 1977
Buku Teks
Stewart, Jeffrey R.
McGraw-Hill , 1980
Buku Teks
Allen, Herman R.
University of Illinois Press, 1964
Buku Teks