Sinclair-Stevenson, 1993
Buku Teks
Turner, Paul, author
Clarendon Press, 1990
Buku Referensi
edited by John L. Bradley and Martin Stevens
Rinehart and Winston, 1968
Buku Teks
Geoffrey, Leech N., author
Longmans, 1993
Buku Teks
Grierson, Herbert John Clifford, Sir, 1866-1960, author
Chatto and Windus, 1950
Buku Teks