Robuta

https://www.scirp.org/reference/ReferencesPapers?ReferenceID=1529167 Pottmann, H. and Wallner, J. (2001) Computational Line Geometry. Springer Heidelberg Dordrecht,... Pottmann, H. and Wallner, J. (2001) Computational Line Geometry. Springer Heidelberg Dordrecht, London, New York.