@article{montufar2014universal,
	Author = {Mont{\'u}far, Guido},
	Journal = {Neural Computation},
	Number = {7},
	Pages = {1386--1407},
	Publisher = {MIT Press},
	Title = {Universal Approximation Depth and Errors of Narrow Belief Networks with Discrete Units},
	Volume = {26},
	Year = {2014},
	}