1. Bernstein S.,On the Index of Clifford Algebra valued singular integral operators and the left linear Riemann problem, Complex Variables, to appear,
2. Bernstein S.,The left linear Riemann problem in Clifford analysis, Bull. Belg. Math. Soc., Simon Stevin,3 (1996), 557–576,
3. Brackx F., R. Delanghe, F. Sommen,Clifford Analysis, Research Notes in Mathematics76, Pitman Advanced Publishing Program, 1982,
4. Delanghe, R., F. Sommen, V. Soucek,Clifford Algebra and Spinor-Valued Functions, MIA 53, Kluwer Academic Publishers, Dordrecht, Boston, London, 1992,
5. LMW/MA;S. Fenyö,1984