1.
Segovia C, Winklmeier M. On the Density of Certain Languages with $p^2$ Letters. Electron. J. Combin. [Internet]. 2015Jul.31 [cited 2026Mar.29];22(3):P3.16. Available from: https://www.combinatorics.org/ojs/index.php/eljc/article/view/v22i3p16