http://www.unu.eduUnited Nations University
http://www.ias.unu.eduUnited Nations University, Institute of Advanced Studies
http://www.undlfoundation.org/UNDL Foundation
http://www.undl.org/unlsys/unl/UNL Specifications.htmOfficial UNL Specification
http://www.vai.dia.fi.upm.es/projects/unl_in.htmlSpanish UNL Homepage
http://www.ailab.lv/unl.htmLatvian UNL Homepage