Mattias Andersson Joachim Gudmundsson Christos Levcopoulos Chips on wafers, or packing rectangles into grids. 95-111 2005 30 Comput. Geom. 2 http://dx.doi.org/10.1016/j.comgeo.2004.05.006 db/journals/comgeo/comgeo30.html#AnderssonGL05