@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},
     mrnumber = {670729},
     zbl = {0494.20020},
     language = {en},
     url = {http://www.numdam.org/item/ITA_1981__15_4_355_0/}
}