@article{ITA_1981__15_4_355_0, author = {Avenhaus, J. and Madlener, K.}, title = {An algorithm for the word problem in $HNN$ extensions and the dependence of its complexity on the group representation}, journal = {RAIRO. Informatique th\'eorique}, pages = {355--371}, publisher = {EDP-Sciences}, volume = {15}, number = {4}, year = {1981}, zbl = {0494.20020}, mrnumber = {670729}, language = {en}, url = {http://www.numdam.org/item/ITA_1981__15_4_355_0/} }