Artikel Jurnal
Hough, Emerson
Grosset &Dunlap, 1922
Buku Teks
White, Patrick, 1912-1990
Penguin Books, [Date of publication not identified]
Buku Teks
White, Patrick, 1912-1990
Penguin Books, 1964
Buku Teks
White, Patrick, 1912-1990
Penguin Books, 1984
Buku Teks