Becher, Johannes R
Buku Teks
Gelhaus, Hermann
Munchen : Max Hueber Verlag, 1975
Buku Teks
Munchen Max Heuber 1973
Buku Teks
Saver, Wolfgang Werner, author
J.B.Metzlersche, 1988
Buku Referensi
Fischer, Watther, author
Heidelberg Carl Winter's Universitatsbuchhandlung 1921
Buku Teks