Cecil, Lord David
Clarendom Press, 1951
Buku Teks
Makarenko, A.S., author
Foreign Languages Publishing House, 1920
Buku Teks
Ackerman, Robert
Cambridge University Press , 1990
Buku Teks
Meredith, Robert C., author
Thomas Y. Crowell, 1967
Buku Teks
Berlin Folk und Wissen Volkseigener verlag 1961
Buku Teks