@article{JRAM_1982__330_152403,
     author = {Robert O. Shelton and Raj P. Soni},
     title = {Aperiodic words on three symbols. {III.}},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {44--52},
     publisher = {mathdoc},
     volume = {330},
     year = {1982},
     zbl = {0467.05010},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1982__330_152403/}
}