Jean-Jacques Lévy Introduction - Bohm's theorem: applications to Computer Science Theory - BOTH 2001. 2001 50 Electr. Notes Theor. Comput. Sci. 2 http://www.elsevier.com/gej-ng/31/29/23/85/28/show/Products/notes/index.htt#001 db/journals/entcs/entcs50.html#Levy01