Dudden, Arthur Power, 1921-, author
University of Pennsylvania Press, 1963
Buku Teks
Horton, Paul B., author
Appleton Century Crofts, 1965
Buku Teks
Townsend, Peter, author
Pinguin Book, 1975
Buku Teks
Cunningham, Jo, author
Learning Matters, 2008
Buku Teks
Horton, Paul B., author
Appleton-Century-Crofts, 1955
Buku Teks