Ferguson, C. E., author
Holt, Rinehart and Winston, 1962
Buku Teks
Ferguson, C. E., author
Holt, Rinehart and Winston, 1965
Buku Teks
Case, Karl E., author
Pearson, 2017
Buku Teks
Fairchild, Fred Rogers, author
Macmillan, 1954
Buku Teks
Case, Karl E., author
Prentice-Hall, 1992
Buku Teks