Dickens, Charles, 1812-1870, author
Percy, 1949
Buku Teks
Bullard, Paddy, author
Cambridge University Press, 2011
eBooks
Ekirch, A. Roger
Cloarendon Press, 1987
Buku Teks
Robbins, Lionel Robbins, Baron, 1898-1984, editor
McMillan & Co., 1952
Buku Teks
Nattrass, Laonora, author
Cambridge University Press, 2003
eBooks