Normal zeta functions of the Heisenberg groups over number rings I: the unramified case. - Michael M. Schein; Christopher Voll (J. Lond. Math. Soc., 2015)

Bolza Quaternion Order and Asymptotics of Systoles Along Congruence Subgroups. - Karin U. Katz; Mikhail G. Katz; Michael M. Schein; Uzi Vishne (Exp. Math., 2016)