[Shoemake91] Shoemake, K., Quaternion Calculus for Animation, Math for SIGGRAPH (ACM SIGGRAPH 91 Course Notes #2), 1991.
[Neilson92] Neilson, G., and Heiland, R., “Animating Rotations Using Quaternions and Splines on a 4D Sphere”, English Edition, Programming and Computer Software, Plenum Pub., New York. 1992.
[Kim95] Kim, M.S. and Nam, K.W., Interpolating Solid Orientations with Circular Blending Quaternion Curves, Computer-Aided Design, Vol. 27, No. 5, pp. 385-398, 1995.