rtryk, "On Rotations as Spin Matrix Polynomials" to appear in J. Phys. A: Math. Theor., arXiv:1408.0767 [math-ph] • T. Curtright, D. B. Fairlie and C. K. Zachos, "A compact formula for rotations as spin matrix polynomials " SIGMA 10 (2014) 084, arXiv:1402.3541 [math-ph] • L. Mezincescu, A. J. Routh and P. K