o pracy Martina Schwalda "On the definition of irreducible holomorphic symplectic manifolds and their singular analogs"

Irreducible symplectic manifolds (ISM) became popular objects to study as together with complex tori and Calabi-Yau manifolds they appear as factors in the Beauville-Bogomolov decomposition theorem. After M. Schwald we shall present an equivalent definition of ISM, which use properties finite quotients of complex tori (flat manifolds).