Helical polynomial curves and double Pythagorean hodographs I. Quaternion and Hopf map representations.

Rida T. Farouki Carlotta Giannelli Alessandra Sestini Helical polynomial curves and double Pythagorean hodographs I. Quaternion and Hopf map representations. 161-179 2009 44 J. Symb. Comput. 2 http://dx.doi.org/10.1016/j.jsc.2008.07.004 db/journals/jsc/jsc44.html#FaroukiGS09