feat(parameter_identification): add Makefile
feat(parameter_identification): add .gitignore
fix(parameter_identification): fix bibstyle

natbib is a style file. It seems that we can use the following bib
styles:

 - plainnat.bst
 - abbrvnat.bst
 - unsrtnat.bst

I picked plainnat.

http://www.ctan.org/tex-archive/macros/latex/contrib/natbib/