Nurdagül Anbar Wilfried Meidl Alev Topuzoglu Idempotent and p-potent quadratic functions: distribution of nonlinearity and co-dimension. 265-291 2017 82 Des. Codes Cryptogr. 1-2 https://doi.org/10.1007/s10623-016-0213-8 db/journals/dcc/dcc82.html#AnbarMT17