A Unified Representation for Morphological, Syntactic, Semantic, and Referential Annotations. - Erhard W. Hinrichs; Sandra Kübler; Karin Naumann (FCA@ACL, 2005)

NPs for Events: Experiments in Coreference Annotation. - Laura Hasler; Constantin Orasan; Karin Naumann (LREC, 2006)