Matthews, Rupert
Miles Kelly, 2007
Buku Teks
Moscati, Sabatino
Routledge & Kegan Paul, 1960
Buku Teks
Branigan, Keith
Heinemann, 1976
Buku Referensi
Caldwell, Wallace Everett
Holt, Rinehart and Winston, 1963
Buku Teks
Turner, Ralph
McGraw-Hill, 1941
Buku Teks