Interesting but short math papers? Is it ok to start a list of interesting, but short mathematical papers, e.g. papers that are in the neighborhood of 1-3 pages? I like to read them here and there throughout the day to learn a new result.
For example, I recently read and liked On the Uniqueness of the Cyclic Group of Order n (Dieter Jungnickel, The American Mathematical Monthly Vol. 99, No. 6 (Jun. - Jul., 1992), pp. 545-547, jstor, doi: 10.2307/2324062).

"The Simple Group of Order 604,801". 
Unfortunately, I can't find it online.
