\Bibitem{Iha72} \by Ya.~Ihara \paper On congruence monodromy problems.~II \jour Matematika \yr 1972 \vol 16 \issue 5 \pages 42--104 \mathnet{http://mi.mathnet.ru/mat656} \mathscinet{https://mathscinet.ams.org/mathscinet-getitem?mr=MR0289519} \zmath{https://zbmath.org/?q=an:0228.14010|0244.14008}