R. Krasauskas, and S. Zube. Proceedings of 9th International Conference on Clifford Algebras and their Applications in Mathematical Physics, Weimar, Germany, (2011)
A. Bobenko, and E. Huhnen-Venedey. (2011)cite arxiv:1101.5955Comment: 39 pages, 30 figures; Theorem 2.7 has been reformulated, as a normalization factor in formula (2.4) was missing. The corresponding formulations have been adjusted and a few typos have been corrected.