Helmut Ulm (born 21 June 1908 in Gelsenkirchen; died 13 June 1975) was a German mathematician who established the classification of countable periodic abelian groups by means of their Ulm invariants.
Helmut Ulm (born 21 June 1908 in Gelsenkirchen; died 13 June 1975) was a German mathematician who established the classification of countable periodic abelian groups by means of their Ulm invariants.