Zurich : Kindler Verlag AG, 1970
Buku Teks
Frenzel, Elizabert
Frankfurt : am Main Athenaum Verlag GmbH, 1967
Buku Teks
RIddle, K. Wilkinson, author
London Arco 1962
Buku Referensi
Kohring, Klause H., author
Munchen Mase Hueber 1973
Buku Referensi
Brewer, E. Cobham, author
New York, Harper Brothers
Buku Referensi