Wikipedia is quickly becoming THE go to reference resource for individuals studying/working in mathematics. This entry on Renewal Theory is evidence of the value that the site can have for both students and working mathematicians:
bzzernt.
Category Archives: statistics
normal/ab-normal
Euler’s 36 Officers Problem
Linked is a fun little paper on the subject of existence results for orthogonal latin squares, written from independent study as an undergraduate
RICHARD R. Tromacek 