Mayer, Henry
Frnklin Watts, 1986
Buku Teks
Sellers, Charles
Rand Mcnally Publishing, 1974
Buku Teks
Goodwin, Doris Kearns, author
St. Martin`s Griffin, 1991
Buku Teks
Swan, Michael, author
Longmans, 1950
Buku Teks
Swan, Michael, author
Longmans Green, 1969
Buku Teks