1. De Brunjin Graph : http://www.cut-the-knot.org/arithmetic/combinatorics/deBruijnCycles.shtml
  2. perfektes matching : http://jorisvr.nl/maximummatching.htm
  3. matching algorithmus written in C : http://www.leda-tutorial.org/de/offiziell/ch05s03s05.html
  4. Hungarian implementaion : http://en.wikipedia.org/wiki/Hungarian_algorithm
  5. graph algorithman in Python : http://www.ece.uci.edu/~chou/py02/python.html
  6. web toan hoc tuoi tre : 

http://www.cut-the-knot.org/

  1. arts of problem solving : 

http://www.artofproblemsolving.com/Forum/portal.php?ml=1

 7 he thong dai hoc vietnam : http://www.ninh-hoa.com/bk-ThuyNguyen_GiaoDucvaThiCu-9.htm

8. Grep command : http://www.thegeekstuff.com/2009/03/15-practical-unix-grep-command-examples/

9. hoc sed: http://www.grymoire.com/Unix/Sed.html

10. eclipse CDT : http://www.eclipse.org/cdt/documentation.php

11. Shannon Behrens Software erfahrung: http://jjinux.blogspot.de/search/label/python

12. Python and vim : http://www.tummy.com/presentations/vimpython-20070225/

13. vim tutorials : http://wiki.ubuntuusers.de/VIM

14. install and configure mingw and msys : http://wiki.openttd.org/Compiling_on_Windows_using_MinGW

15. configure msys : http://www.mingw.org/wiki/MSYS

16. Das Buch Shell-Programmierung Jürgen Wolf: http://openbook.galileocomputing.de/shell_programmierung/

17. sed sample script and tutorial : http://sed.sourceforge.net/grabbag/tutorials/

18. apps für Samsung S5620 monte : http://www.mobileheart.com/cell-phone-softwares/2141-Samsung-S5620-Monte-Software.aspx

19. shell programming : http://www.pronix.de/pronix-1.html

20. command find in DOS :http://technet.microsoft.com/en-us/library/bb490906.aspx

21. Linux Magazin : http://www.linux-mag.com/id/1355/

22. Grepmail : http://www.softpanorama.org/Tools/grepmail.shtml