text: *[http://www.google.com/patents?id=l5wdAAAAEBAJ&dq=ininventor:%22heinz+falk%22&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2008&as_maxm_ap=1&as_maxy_ap=2008&as_drrb_is=q&as_minm_is=1&as_miny_is=2008&as_maxm_is=1&as_maxy_is=2008 Process for the N-alkylation or ureas] US Pat. 5124451 - Filed Jul 10, 1991 - Chemie Linz GmbH
  *[http://www.google.com/patents?id=va8fAAAAEBAJ&dq=ininventor:%22heinz+falk%22&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2008&as_maxm_ap=1&as_maxy_ap=2008&as_drrb_is=q&as_minm_is=1&as_miny_is=2008&as_maxm_is=1&as_maxy_is=2008 Process for the N-alkylation of ureas] US Pat. 5169954 - Filed Dec 16, 1991 - Chemie Linz GmbH
  *[http://www.google.com/patents?id=K7ccAAAAEBAJ&dq=ininventor:%22heinz+falk%22&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2008&as_maxm_ap=1&as_maxy_ap=2008&as_drrb_is=q&as_minm_is=1&as_miny_is=2008&as_maxm_is=1&as_maxy_is=2008 Process for the preparation of pure N,N'-asymmetrically substituted phenylureas] US Pat. 5283362 - Filed Jul 31, 1992 - Chemie Linz GmbH
  *[http://www.google.com/patents?id=XU4aAAAAEBAJ&dq=5360601 Process for the preparation of Isocyanic Acid by Decomposition of N,N-trisubstituted Ureas] Eur. Pat. EP 0582863A2 - Filed Feb 16, 1994 - US Pat. Nr. 5360601 Filed Nov 1, 1994 - Chemie Linz GmbH
  *Isocyanates by Decomposition of N,N,N-trisubstituted Ureas Eur. Pat. EP 0583637A1 - Filed Feb 23, 1994 - Chemie Linz GmbH
  *[http://www.google.com/patents?id=XBUbAAAAEBAJ&dq=ininventor:%22heinz+falk%22&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2008&as_maxm_ap=1&as_maxy_ap=2008&as_drrb_is=q&as_minm_is=1&as_miny_is=2008&as_maxm_is=1&as_maxy_is=2008 Amine-oxides] US Pat. 5409532 - Filed Jan 21, 1993 - Lenzing AG