TY - JOUR A1 - Arworn, Srichan A1 - Denecke, Klaus-Dieter T1 - Tree Transformations defined by Hypersubstitutions Y1 - 2001 UR - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/18172 SN - 1509 - 9415 ER -