@article{RCM_1980__14_181690,
     author = {Klaus Madlener and J\"urgen Avenhaus},
     title = {String {Matching} {And} {Algorithmic} {Problems} {In} {Free} {Groups.}},
     journal = {Revista colombiana de matematicas},
     pages = {1--16},
     publisher = {mathdoc},
     volume = {14},
     year = {1980},
     zbl = {0431.03031},
     url = {http://geodesic.mathdoc.fr/item/RCM_1980__14_181690/}
}