qrst

http://www.mathpages.com

Mississippi State University
http://www.erc.msstate.edu/publications/gridbook

University of Illinois at Urbana-Champaign
http://www.geom.uiuc.edu/docs/reference/CRC-formulas

Louisiana State University
http://www.phys.lsu.edu/astro/H_Book.current/Appendices/Mathematics/operators.shtml
http://www.phys.lsu.edu/astro/H_Book.current/Appendices/Mathematics/scale.factors.shtml

Finite Mathematics and Applied Calculus Resource Page
http://people.hofstra.edu/faculty/Stefan_Waner

Drexel University
http://mathforum.org/
http://mathforum.org/library/toc.html