Shashi Kiran Chilappagari Anantha Raman Krishnan Bane V. Vasic LDPC Codes Which Can Correct Three Errors Under Iterative Decoding http://arxiv.org/abs/0801.1282 2008 CoRR abs/0801.1282 db/journals/corr/corr0801.html#abs-0801-1282 informal publication