# 1.6. Citing scientific work¶

Whenever you add a feature based on a scientific publication, it should be cited properly:

1. Add an item to the file data/references.bib. Include the doi if possible. (The url field can be used as an alternative if the doi is not available.) Maintain the chronological order. Do not use reference manager software to edit this file. Use a plain text editor instead and don’t touch existing references if not needed.
2. Add log.cite('someref', 'a reason') to the code based on the publication, e.g.log.cite('marques2012', 'using LibXC, the library of exchange and correlation functionals'). This guarantees that paper is properly cited at the end of the HORTON screen output.