Ditkin's Condition and Primary Ideals in Central Beurling Algebras. Richard D. Mosak (1978) Monatshefte für Mathematik
Duals of Orbit Spaces in Groups With Relatively Compact Inner Automorphism Groups Are Hypergroups. R.W. Henrichs, K. Hartmann, R. Lasser (1979) Monatshefte für Mathematik