Robenso, James Harvey
Ginn , 1931
Buku Teks
Viorst, Milton
Chilton Book Company, 1967
Buku Teks
Burns, Edward McNall, 1897-1972
W.W Norton, 1980
Buku Teks
Boak, Arthur E.R.
Appleton-Century-Crofts, 1951
Buku Teks SO
edited by V.A.C. Gatrell, Bruce Lenman, and Geoffrey Parker
Europa Publications, 1980
Buku Referensi