RELION/Link

http://www2.mrc-lmb.cam.ac.uk/relion/index.php/Main_Page
https://github.com/jjcorreao/relion/tree/master/relion-1.3
http://www2.mrc-lmb.cam.ac.uk/groups/scheres/relion13_tutorial.pdf
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4318617
http://www.sciencedirect.com/science/article/pii/S1047847712002481