@article{RSMUP_1986__75__247_0,
     author = {D'Este, Gabriella},
     title = {Extended strings and admissible words},
     journal = {Rendiconti del Seminario Matematico della Universit\`a di Padova},
     pages = {247--251},
     publisher = {Seminario Matematico of the University of Padua},
     volume = {75},
     year = {1986},
     mrnumber = {847669},
     zbl = {0602.16026},
     language = {en},
     url = {http://www.numdam.org/item/RSMUP_1986__75__247_0/}
}