Squibs: Prepositional Phrase Attachment without Oracles Michaela Atterer author Hinrich Schütze author 2007 text journal article Computational Linguistics continuing periodical academic journal atterer-schutze-2007-squibs 10.1162/coli.2007.33.4.469 https://aclanthology.org/J07-4002/ 2007 33 4 469 476