Sébastien Ferenczi Zoltán Kása Complexity for Finite Factors of Infinite Sequences. 177-195 1999 218 Theor. Comput. Sci. 1 db/journals/tcs/tcs218.html#FerencziK99 http://dx.doi.org/10.1016/S0304-3975(98)00258-8