Donaldson, Dwight M., author
Luzac & Company, 1933
Buku Teks
Browne, Edward G., author
Cambridge University Press , 1956
Buku Teks
Sykes, Percy Molesworth
Macmillan and co., limited, 1930
Buku Teks
Browne, Edward G., author
Cambridge University Press, 1959
Buku Teks
Artikel Jurnal