Heinz Bachmann

Heinz Bachmann (1924 – 22 April 2022) was a mathematician who worked at the Eidgenössische Sternwarte (federal observatory) in Zürich. He introduced the Bachmann–Howard ordinal and ordinal collapsing functions. Provided by Wikipedia

1
by Bachmann, Heinz
Published 1955
Springer Berlin Heidelberg

2
by Bachmann, Heinz
Published 1967
Springer Berlin Heidelberg