Porter, Hal
Thomas Nelson and Sons, 1974
Koleksi Publik
University of Newcatle, 1984
Buku Teks
edited by RMW Dixon and Martin Duwell
University of Queensland, 1990
Buku Teks
Cosbuc, George, author
Minerva, 1980
Buku Teks
Yeats, W.B., author
Everyman's Library, 1992
Buku Referensi