Sabine Leveiller Joseph Boutros Philippe Guillot Gilles Zémor Cryptanalysis of Nonlinear Filter Generators with {0, 1}-Metric Viterbi Decoding. 402-414 2001 conf/ima/2001 IMA Int. Conf. http://link.springer.de/link/service/series/0558/bibs/2260/22600402.htm db/conf/ima/ima2001.html#LeveillerBGZ01