db/conf/coopis/SturmML97.html Rose Sturm Jutta A. Mülle Peter C. Lockemann Collision of Constrained Work Spaces: A Unifying Concept for Design Interactions. 25-35 COOPIS1997/79460025.pdf 1997 conf/coopis/97 CoopIS http://computer.org/proceedings/coopis/7946/79460025abs.htm db/conf/coopis/coopis97.html#SturmML97