Constructions of automorphic forms and related cohomology classes for arithmetic subgroups of $G_2$

Li, Jian-Shu; Schwermer, Joachim

Compositio Mathematica, Volume 87 (1993) p. 45-78

Non-existence of singular cusp forms

Li, Jian-Shu

Compositio Mathematica, Volume 83 (1992) p. 43-51