Stursberg, Peter
Doubleday Canada Limited, 1978
Buku Teks
Juric, Dusan
Beograd, Yugoslavija [t.th.] [t.p.]
Buku Teks
Manzer, Ronald A., author
McGraw-Hill , 1974
Buku Teks
Spiljak, Mika
Publicisticko-Izdavacki Zavod, 1961
Buku Teks
edited by Robert A. Goldwin
Rand McNally, 1963
Buku Teks