Tutorials and documentation concerning maths with LaTeX:
- Mathmode
by Herbert Voss
Extensive collection of materials concerning mathematics with TeX and LaTeX, highly recommended - amsmath user’s guide
American Mathematical Society
Documentation for the math package - Math into LaTeX
by George Grätzer - Short Math Guide for LaTeX
by Michael Downes
concise summary of recommended features in LaTeX and extension packages for writing math formulas - Using the amsthm Package
American Mathematical Society
Enhancements of the LateX theorem environment - Höhere Mathematik

chapter 8 of the german edition of the LaTeX Companion by Mittelbach, Gossens - Mathematik mit LaTeX

easy introduction by Jana Peters



