Niels Erik NørlundNiels Erik Nørlund (26 October 1885, in Slagelse – 4 July 1981, in Copenhagen) was a Danish mathematician.
His book ''Vorlesungen über Differenzenrechnung'' (1924, reprinted 1954) was the first book on complex function solutions of difference equations. His doctoral students include Georg Rasch.
The Norlund Alps and Norlund Land in Greenland were named after him. Provided by Wikipedia