• Dan Suciu, Limsoon Wong,
  On Two Forms of Structural Recursion
  In Proceedings of the Fifth International Conference on Database Theory, pp. 111-124, January, 1995
  
• Peter Buneman, Leonid Libkin, Dan Suciu, Val Tannen, Limsoon Wong,
  Comprehension Syntax
  Published in SIGMOD Record, vol. 23 , no. 1 , pp. 87-96 , March , 1994