Friedrich Eisenbrand Stefan Funke Andreas Karrenbauer Joachim Reichel Elmar Schömer Packing a Truck - Now with a Twist! 505-527 2007 17 Int. J. Comput. Geometry Appl. 5 http://dx.doi.org/10.1142/S021819590700246X db/journals/ijcga/ijcga17.html#EisenbrandFKRS07