questions on donald judd

Links
http://www.artincontext.org/artist/j/donald_judd/index.htm
http://www.artsconnected.org/artsnetmn/whatsart/judd.html
http://www.mamac-nice.org/francais/exposition_tempo/musee/judd/dossier.html
http://www.guggenheimcollection.org/site/artist_bio_70.html