Bernd Kiefer Hans-Ulrich Krieger Detlef Prescher A Novel Disambiguation Method for Unification-Based Grammars Using Probabilistic Context-Free Approximations. 2002 COLING http://acl.ldc.upenn.edu/C/C02/C02-1075.pdf db/conf/coling/coling2002.html#KieferKP02