Glover, John Desmond, author
Richard D. Irwin, 1957
Buku Teks
Maier, Norman R.F., author
Hougtton-Mifflin, 1965
Buku Teks
Yoder, Dale, author
Prentice-Hall, 1962
Buku Teks
Lovejoy, Laurence C., author
Aleander Hamilton Institute, 1962
Buku Teks
Yoder, Dale, author
Prentice-Hall, 1984
Buku Teks