@article{ITA_1982__16_3_191_0,
     author = {Ross, Rockford and Winklmann, Karl},
     title = {Repetitive strings are not context-free},
     journal = {RAIRO. Informatique th\'eorique},
     pages = {191--199},
     publisher = {EDP-Sciences},
     volume = {16},
     number = {3},
     year = {1982},
     mrnumber = {686912},
     zbl = {0489.68071},
     language = {en},
     url = {http://www.numdam.org/item/ITA_1982__16_3_191_0/}
}