1. P. Lounesto, Introduction to Clifford Algebras, Lecture 1 in Lectures on Clifford Geometric Algebras, ed. by R. Abłamowicz and G. Sobczyk, Birkhäuser, Boston, 2004.
2. W. R. Hamilton, Elements of Quaternions, Vols. I and II, a reprint of the 1866 edition published by Longmans Green (London) with corrections by C. J. Jolly, Chelsea, New York, 1969.
3. S. L. Adler, Quaternionic Quantum Mechanics and Quantum Fields, Oxford U. Press, New York, 1995.
4. P. Lounesto, Clifford Algebras and Spinors, second edition, Cambridge University Press, Cambridge (UK), 2001.
5. W. E. Baylis, editor, Clifford (Geometric) Algebra with Applications to Physics, Mathematics, and Engineering, Birkhäuser, Boston, 1996.