[[1] W. Kuperberg, The set of packing and covering densities of convex disks, http://arxiv.org/pdf/1309.0281v1.pdf, (2013).]Search in Google Scholar
[[2] Hai-Chau Chang, Lih-Chung Wang, A Simple Proof of Thues Theorem on Circle Packing, http://arxiv.org/pdf/1009.4322.pdf, (2010).]Search in Google Scholar
[[3] K. Böröczky jr., Finite Packing and Covering, Cambridge University Press, (2004).10.1017/CBO9780511546587]Search in Google Scholar
[[4] C. A. Rogers, Packing and Covering, Cambridge, University Press, (1964).]Search in Google Scholar
