After working with references and citations in latex for a while, with multiple files, I noticed that some things need improvement. First of all, you need to use some way to store your bibliography outside of the tex file. For instance, using bibtex. Second, you probably want some bibliography package, such as biblatex or natbib. Third, you need some way to manage your bibliography entries and verify if they are correct.
For the third option, I didn't found a good enough option, for my needs (light, easy, command line). Thinking about this problem, I decided to create a tool exactly for that. Some things I want(ed) are to read from tex file to discover the keys; add the entries reading a bib file; and obtaining from the internet the correct bibliography entry.
The tool is still in very early development, but is already available for checking on github.