T. Seifried, C. Rendl, M. Haller, and S. Scott. CHI '12: Proceedings of the 30th international conference on Human factors in computing systems, page 2855--2864. New York, NY, USA, ACM, (May 2012)
S. Karisch, F. Rendl, and H. Wolkowicz. Quadratic Assignment and Related Problems, volume 16 of DIMACS Series in Discrete Mathematics and Theoretical Computer Science, page 199-219. DIMACS/AMS, (1993)
P. Pardalos, F. Rendl, and H. Wolkowicz. Quadratic Assignment and Related Problems, volume 16 of DIMACS Series in Discrete Mathematics and Theoretical Computer Science, page 1-42. DIMACS/AMS, (1993)