Patric R. J. Östergård Jörn Quistorff Alfred Wassermann New Results on Codes with Covering Radius 1 and Minimum Distance 2. 241-250 2005 35 Des. Codes Cryptography 2 http://dx.doi.org/10.1007/s10623-005-6404-3 db/journals/dcc/dcc35.html#OstergardQW05