@article {HirschPapaVava,
	title = {Exponential lower bounds for finding Brouwer fixed points},
	journal = {Journal of Complexity},
	volume = {5},
	year = {1989},
	pages = {379{\textendash}416},
	author = {M. D. Hirsch and C. H. Papadimitriou and S. A. Vavasis}
}