@article {PRRV15,
   author = {Parreau, Aline and Rigo, Michel and Rowland, Eric and Vandomme, Elise},
   title = {A new approach to the $2$-regularity of the $\ell$-abelian complexity of $2$-automatic sequences},
   journal = {Electronic Journal of Combinatorics},
year={2015},
volume={22},
issue={1}
}