R. Subramanian. PENDS: an approach to modeling and retrieving "pending" information. In Frederick H. Lochovsky, Robert B. Allen, editors, Proceedings of the ACM SIGOIS and IEEE CS TC-OA Conference on Office Information Systems, COCS 1990, Cambridge, Massachusetts, USA, April 25-27, 1990. pages 158-162, ACM, 1990. [doi]