Positivity of Dunkl’s intertwining operator
M. Rösler, Duke Mathematical Journal 98 (1999) 445–463.

Partial Characters and Signed Quotient Hypergroups
M. Rösler, M. Voit, Canadian Journal of Mathematics 51 (1999) 96–116.

On the dual of a commutative signed hypergroup
M. Rösler, Manuscripta Mathematica 88 (1995) 147–163.

A note on property (T) of orthogonal polynomials
R. Lasser, M. Rösler, Archiv Der Mathematik 60 (1993) 459–463.