1. F. Brackx, R. Delanghe, and F. Sommen, Clifford Analysis, Pitman, Boston, London, Melbourne, 1982.
2. P. Cerejeiras, Decomposition of analytic hyperbolically harmonic functions. Proceedings of Clifford Algebras and their Applications, Aachen, Kluwer, Dordrecht (1998), 45–51.
3. J. Cnops, Hurwitz pairs and applications of Möbius transformation, Habilitation thesis, Univ. Gent, 1994.
4. J. Gilbert and M. Murray, Clifford algebras and Dirac operators in harmonic analysis, Cambridge studies in advanced mathematics 26, Cambridge, New York 1991.
5. S.-L. Eriksson-Bique, Comparison of quaternionic analysis and its modification, in Harlow: Longman. Pitman Res. Notes Math. Ser. 394, 1998, 109–121.