Reference:
  Author: Sjors H. W. Scheres
  Title: "RELION: implementation of a Bayesian approach to cryo-EM structure determination"
  Journal: J Struct Biol.
  Year: 2012
  Year: 180
  Number: 3
  Pages: 519-30
  DOI: 10.1016/j.jsb.2012.09.006
  PMID: 23000701
  URL: http://www.sciencedirect.com/science/article/pii/S1047847712002481
