Evgeny Lipovetsky Nira Dyn An efficient algorithm for the computation of the metric average of two intersecting convex polygons, with application to morphing. 269-282 2007 26 Adv. Comput. Math. 1-3 http://dx.doi.org/10.1007/s10444-005-7473-6 db/journals/adcm/adcm26.html#LipovetskyD07