\bibitem{TAA03a} Abou-Assaleh, Tony, Cercone, Nick, and Keselj, Vlado. \newblock Expressing Probabilistic Context-Free Grammars in the Relaxed Unification Formalism. \newblock In {\em Proceedings of the Conference Pacific Association for Computational Linguistics, PACLING'03\/.} Dalhousie University, Halifax, Nova Scotia, Canada, August 2003, pp.~29--36.