List of useful informative webpages categorized by topics.
Shell Scripting
- Bash Shell Programming in Linux, P. Lutus (2006)
- Linux I/O Redirection (2005)
- Linux Shell Scripting Tutorial. A Beginner’s handbook, Vivek G. Gite (2002)
LaTeX
- Latex @ WikiBooks
- Tips and tricks for LaTeX and friends, Kjell Magne Fausk (2006)
- Formulas in LaTeX @ Wikipedia
- LaTeX symbols
- PGF and TikZ examples gallery