Our work with openSNP has been published in PLOS ONE in 2014. If you are re-using code or use data from openSNP it would be great if you could cite the paper, so we also see where people are putting the project to good use.
If you're using bibtex you can use the following code:
@article{greshake2014opensnp,
title={OpenSNP-a crowdsourced web resource for personal genomics},
author={Greshake, Bastian and Bayer, Philipp E and Rausch, Helge and Reda, Julia},
journal={PLOS ONE},
volume={9},
number={3},
pages={e89204},
year={2014},
doi={10.1371/journal.pone.0089204}
url={http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0089204}
publisher={Public Library of Science}
}