Rachwald, Arthur R.
Westview Press, 1983
Buku Teks
Buku Teks
Gumkowski, Janusz
Polonia Pub. House, 1961
Buku Teks
Wangler, Alexandra
VS Verlag, 2012
eBooks
Chukovsky, Nikolai, author
Foreign Languages Publishing House , [Date of publication not identified]
Buku Teks