Department of Public Information. United Nations
Department of Public Information, 2000
Buku Teks
United Nation, 1992
Majalah, Jurnal, Buletin
Goodrich, Leland M., author
Thomas Y. Crowell, 1961
Buku Teks
edited by Gesina H.J. van der Molen, Willem Petrus Josef Pompe, J.H.W. Verzyl
Nederlandse Studentenvereniging, 1956
Buku Teks
Bowett, D. W. (Derek William), author
Frederck A. Praeger, 1964
Buku Teks