Routledge, 1998
Buku Teks
Blake, Frank R.
[publisher not identified], 1912
Buku Klasik
Burrow, T.
Clarendon Press, 1961
Buku Referensi
Meyer-Lubke, W.
Carl Winter's Universitatsbuchhandlung, 1935
Buku Referensi
Cambridge University Press, 1993
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