Phythian, B. A.
Hodder & Stoughton, 1986
Buku Referensi
Phythian, B.A.
London Hodder & Stoughton 1992,
Buku Teks
Makkink, H.J.
Nijgh and Van Ditmar, 1951
Buku Teks
Newby, Michael
Cambridge University Press, 1988
Buku Teks
Woods, Geraldine
John Wiley & Sons, 2015
Buku Teks