Anselm Blumer Andrzej Ehrenfeucht David Haussler Manfred K. Warmuth Learnability and the Vapnik-Chervonenkis dimension. 929-965 1989 36 J. ACM 4 http://doi.acm.org/10.1145/76359.76371 db/journals/jacm/jacm36.html#BlumerEHW89