Paul Gustav Samuel Stäckel (20 August 1862 — 12 December 1919) was a German mathematician, active in the areas of differential geometry, number theory, and non-Euclidean geometry. In the area of prime number theory, he used the term twin prime for the first time.[citation needed]

External links

* O'Connor, John J.; Robertson, Edmund F., "Paul Stäckel", MacTutor History of Mathematics archive, University of St Andrews, http://www-history.mcs.st-andrews.ac.uk/Biographies/Stackel.html .
* Paul Stäckel at the Mathematics Genealogy Project