Petr Pajas, Jan Štěpánek (2006):XML-Based Representation of Multi-Layered Annotation in the PDT 2.0. In: Proceedings of the LREC Workshop on Merging and Layering Linguistic Information (LREC 2006), pp. 40-47, ELRA, Genova, Italy, ISBN 2-9517408-2-4 (url, bibtex)