@incollection {jue:99d, author = {J. Hoschek and B. J{\"u}ttler}, title = {Techniques for fair and shape--preserving surface fitting with tensor--product {B}-splines}, booktitle = {Shape Preserving Representations in Computer Aided Design (J.M. Pe\~na, ed.)}, pages = {163--185}, publisher = {Nova Science publishers}, address = {New York, NY}, year = {1999} }