On the geometric boundaries of hyperbolic 4-manifolds. Long, D.D.; Reid, A.W. — 2000 Geometry & Topology
Algorithmic compression of surface automorphisms. A.J., Long, D.D. Casson — 1985 Inventiones mathematicae
All flat manifolds are cusps of hyperbolic orbifolds. Long, D.D.; Reid, A.W. — 2002 Algebraic & Geometric Topology