Israel, Saul, author
Holt, Rinehart and Winston, 1976
Buku Teks
Israel, Saul, author
Holt, Rinehart and Winston, 1980
Buku Teks
Federico, Ronald C., author
McGraw-Hill, 1990
Buku Teks
Harris, Jonathan, author
Bloomsbury , 2014
Buku Teks
McNally, Rand, author
Rand McNally & Co, 1963
Buku Referensi