TY - CONF AU - Böttcher, Stefan AU - Hartel, Rita AU - Jacobs, Thomas AU - Jeromin, Markus ID - 15088 SN - 0302-9743 T2 - Data Science - 30th British International Conference on Databases, BICOD 2015 TI - ECST – Extended Context-Free Straight-Line Tree Grammars ER -