https://sibi.upn.mx/cgi-bin/koha/opac-search.pl?q=ccl=se%2Cphr%3A%22DG%2091%20%3B%22&sort_by=title_az&format=rss 3 0 50 ISBN: https://sibi.upn.mx/cgi-bin/koha/opac-detail.pl?biblionumber=757 [Ginebra] : UNESCO, 1991 .
8 p.

]]> Place hold on Address by Federico Mayor at the ceremony for presentation of the 1991 Sultan Qaboos Prizefor enviromental preservation :

]]> https://sibi.upn.mx/cgi-bin/koha/opac-detail.pl?biblionumber=757 ISBN: https://sibi.upn.mx/cgi-bin/koha/opac-detail.pl?biblionumber=758 París : UNESCO, 1991 .
6 p.

]]> Place hold on Address by Federico Mayor at the opening of the International Forum on Sustainable Development, París, 23 September 1991 /

]]> https://sibi.upn.mx/cgi-bin/koha/opac-detail.pl?biblionumber=758 ISBN: https://sibi.upn.mx/cgi-bin/koha/opac-detail.pl?biblionumber=18434 Salamanca [Esp.] : UNESCO, 1991 .
7 p.

]]> Place hold on Education for peace :

]]> https://sibi.upn.mx/cgi-bin/koha/opac-detail.pl?biblionumber=18434