@article{SF_1983__26_134604,
     author = {A. Ehrenfeucht and G. Rozenberg},
     title = {On the size of the subword complexity of square-free {DOL} languages.},
     journal = {Semigroup forum},
     pages = {215--224},
     publisher = {mathdoc},
     volume = {26},
     year = {1983},
     zbl = {0512.68058},
     url = {http://geodesic.mathdoc.fr/item/SF_1983__26_134604/}
}