1. Heyer, H.: Probability theory on a hypergroup: a survey. In: Lect. Notes Math., vol. 1064, pp. 481–550. Springer, Berlin Heidelberg New York (1984)
2. Lasser, R.: Orthogonal polynomials and hypergroups. Rend. Mat. Appl. 2, 185–209 (1983)
3. Locher, F.: Numerische Mathematik für Informatiker. Springer, Berlin Heidelberg New York (1992)
4. Pavel, L.: Hipergrupuri. Editura Academiei Române, Bucharest (2000)
5. Polyanin, A.D., Manzhirov, A.V.: Handbook of Mathematics for Engineers and Scientists. Chapman & Hall/CRC Taylor & Francis Group, Boca Raton, London, New York (2007)