@incollection {jue:94b,
 author = {B. J{\"u}ttler and R. Dietz},
 title = {A Geometrical Approach to Interpolation on Quadric Surfaces},
booktitle = {Curves and surfaces in geometric design (P. J. Laurent et al., eds.)}, 
 pages = {251--258},
publisher = {AK Peters},
 address = {Wellesley MA},
 year = {1994}
}