Shashi Kiran Chilappagari Dung Viet Nguyen Bane V. Vasic Michael W. Marcellin On Trapping Sets and Guaranteed Error Correction Capability of LDPC Codes and GLDPC Codes http://arxiv.org/abs/0805.2427 2008 CoRR abs/0805.2427 db/journals/corr/corr0805.html#abs-0805-2427 informal publication