Gustavo Oliveira
Exploring Spring Models. Gamasutra. 
http://www.gamasutra.com/features/20011005/oliveira_01.htm

Takayuki Itoh, Yumi Yamaguchi, Yuko Ikehata, Yasumasa Kajinaga
Hierarchical Data Visualization Using a Fast Rectangle-Packing Algorithm 
<http://ieeexplore.ieee.org/iel5/2945/28480/01272729.pdf?arnumber=1272729>

Claire Kenyon, Eric Remila
A Near-Optimal Solution to a Two-Dimensional Cutting Stock Problem
<http://citeseer.csail.mit.edu/608790.html>

Yuk-On Tam, Yu-Liang Wu, Wenqi Huang, Chak-Kuen Wong.
An Effective Quasi-Human Based Heuristic for Solving Rectangle Packing Problem
<http://ieeexplore.ieee.org/iel4/5991/16025/00743677.pdf?arnumber=743677>

Hiroshi Murata, Kunihiro Fujiyoshi, Shigetoshi Nakatake, Yoji Kajitani
Rectangle-Packing-Based Module Placement.
Japan Advanced Institute of Science and Technology. 
<http://delivery.acm.org/10.1145/230000/225094/p472-murata.pdf?key1=225094&key2=3997959311&coll=portal&dl=ACM&CFID=68144886&CFTOKEN=17499262>

Mediating Photo Collage Authoring.
College of Computing, Georgia Institute of Technology. 
<http://delivery.acm.org/10.1145/1100000/1095065/p183-diakopoulos.pdf?key1=1095065&key2=8711380411&coll=GUIDE&dl=GUIDE&CFID=69694919&CFTOKEN=42025419>

Junhwan Kim, Fabio Pellacini
JigSaw Image Mosaics.
Cornell University.
<http://www.cs.cornell.edu/People/jkim/JIM/JigsawImageMosaics.pdf>

S Greenberg, M Rounding
The Notification Collage.
University of Calgary.
<http://portal.acm.org/ft_gateway.cfm?id=365339&type=pdf&dl=GUIDE&dl=ACM&CFID=11111111&CFTOKEN=2222222>

Andruid Kerne
CollageMachine
<http://www.andruid.com/papers/andruidLeonardo33-5.PDF>