Jim Gindling Andri Ioannidou Jennifer Loh Olav Lokkebo Alexander Repenning LEGOsheets: A Rule-Based Programming, Simulation and Manipulation Environment for the LEG0 Programmable Brick. 172-179 1995 VL http://computer.org/proceedings/vl/7045/70450172abs.htm db/conf/vl/vl95.html#GindlingILLR95