Rozmaryn, Stefan, author
Polonia Publishing House , 1958
Buku Teks
Lange, Oktavii Konstantinovich, 1883-1975
Polonia Pub. House, 1957
Buku Teks
Dobrowolski, Marian, author
Polonia Publishing House, 1960
Buku Teks
Wangler, Alexandra
VS Verlag, 2012
eBooks
The World Bank, 1995
Buku Teks