Ernst Leonard Lindelöf
Ernst Leonard Lindelöf ( ; 7 March 1870 – 4 June 1946 ) was a Finnish mathematician , who made contributions in real analysis , complex analysis and topology . 
<triplet> Ernst Leonard Lindelöf <subj> 7 March 1870 <obj> date of birth <subj> 4 June 1946 <obj> date of death <subj> topology <obj> field of work