VATANSEVER, B. Efficient presentations of the group $\mathrm{PSL}(2, Z_n) \times \mathrm{PSL}(2, Z_m)$, for certain $n$, $m$. MATHEMATICA SCANDINAVICA, [S. l.], v. 80, p. 188–194, 1997. DOI: 10.7146/math.scand.a-12618. Disponível em: https://www.mscand.dk/article/view/12618. Acesso em: 4 may. 2024.