Jan Odijk, Martijn van der Klis and Sheean Spoel (2018). “Extensions to the GrETEL treebank query application” In: Proceedings of the 16th International Workshop on Treebanks and Linguistic Theories. Prague, Czech Republic. pp. 46-55.
GrETEL stands for Greedy Extraction of Trees for Empirical Linguistics. It is a user-friendly search engine for the exploitation of syntactically annotated corpora or treebanks. If you are new to GrETEL we recommend you to take a look at the documentation.