Srinivas Raghothama Vadim Shapiro Topological Framework for Part Families. 246-255 2002 2 J. Comput. Inf. Sci. Eng. 4 http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JCISB6000002000004000246000001&idtype=cvips&gifs=Yes db/journals/jcise/jcise2.html#RaghothamaS02