1. B. Addis, M. Locatelli, F. Schoen, Disk packing in a square: a new global optimization approach, Optimization Online 1229 (2005).
2. Improving dense packings of equal disks in a square;Boll;Electron. J. Combin.,2000
3. L.G. Casado, I. Garcia, P. Szabö, T. Csendes, Equal circles packing in square II: new results for up to 100 circles using the TAMSASS-PECS algorithm, in: F. Giannessi, P. Pardalos, T. Rapcsak (Eds.), Optimization Theory: Recent developements from Mátraháza, Kluwer Academic Publishers, Dordrecht, 1998, pp. 207–224.
4. I. Castillo, F.J. Kampas, J.D. Pinter, Solving circle packing problems by global optimization: Numerical results and industrial applications, European, J. Oper. Res, to appear.
5. C. de Groot, R. Peikert, D. Würtz, M. Monagan, Packing circles in a square: a review and new results, in: System Modelling and Optimization, Proceedings of the 15th IFIP Conference, Zürich, 1991, pp. 45–54.