On the critical pair theory in abelian groups: Beyond Chowla's Theorem.

Yahya Ould Hamidoune Oriol Serra Gilles Zémor On the critical pair theory in abelian groups: Beyond Chowla's Theorem. 441-467 2008 28 Combinatorica 4 http://dx.doi.org/10.1007/s00493-008-2262-8 db/journals/combinatorica/combinatorica28.html#HamidouneSZ08