Practical Annotation Scheme for an HPSG Treebank of Bulgarian Kiril Simov author Petya Osenova author 2003 text Proceedings of 4th International Workshop on Linguistically Interpreted Corpora (LINC-03) at EACL 2003 conference publication simov-osenova-2003-practical https://aclanthology.org/W03-2403/ 2003