Selçuk Kavut Subhamoy Maitra Sumanta Sarkar Melek D. Yücel Enumeration of 9-Variable Rotation Symmetric Boolean Functions Having Nonlinearity > 240. 266-279 2006 conf/indocrypt/2006 INDOCRYPT http://dx.doi.org/10.1007/11941378_19 db/conf/indocrypt/indocrypt2006.html#KavutMSY06