### Articles

Selected articles of Knopp include:

- (in German)
- (in German)
- (in German)
- (in German)
- (in German)
- (in German)

He was the co-founder of Mathematische Zeitschrift (in which the majority of his above-cited articles are published) in 1918, being the editor from 1934 to 1952.

After retirement Knopp continued to do mathematics, publishing for example

and delivering the lecture

*Folgenräume und Limitierungsverfahren* at the first meeting of the International Mathematics Union in 1952.

### Books

Knopp's mathematical research was on "generalized limits" and he wrote two books on sequences and series:

He also authored two texts on functions of a complex variable as well as a problem book:

He also produced the sixth edition of the three-volume work (a fourth volume was later added by Friedrich Lösch in 1980):