Wilson, Dick, author
Penguin Books, 1972
Buku Teks
Link, Arthur S., author
University of Pennsylvania Press , 1957
Buku Teks
Wilson, Kathleen J. W.
Churchill livingstone, 1998
Buku Teks
Waugh, Anne
Churchill Livingstone, 2010
Buku Teks
Waugh, Anne, author
Churchill Livingstone, 2007
Buku Teks