@article{VolkertZierhutSchieleetal.2014,
  author    = {Julia Volkert and Kathrin C. Zierhut and Miriam A. Schiele and Martina Wenzel and Juliane Kopf and Sarah Kittel-Schneider and Andreas Reif},
  title     = {Predominant polarity in bipolar disorder and validation of the polarity index in a German sample},
  doi       = {10.1186/s12888-014-0322-8},
  year      = {2014},
}