Roman Durikovic Silvester Czanner Július Parulek Milos Srámek Heterogeneous Modeling of Biological Organs and Organ Growth. 239-258 2008 Heterogeneous Objects Modelling and Applications http://dx.doi.org/10.1007/978-3-540-68443-5_10 series/lncs/4889 db/series/lncs/lncs4889.html#DurikovicCPS08