S. Dughmi. (2009)cite arxiv:0912.0322Comment: This revision corrects an error in definition 2.2, as well as provides additional intuition regarding the definitions of convex closure and concave closure.
M. Aldridge, O. Johnson, and J. Scarlett. (2019)cite arxiv:1902.06002Comment: Survey paper, 140 pages, 19 figures. To be published in Foundations and Trends in Communications and Information Theory.