Hartmuth, K., van Santen, M. A., & Lührmann, R. (2012). Ultracentrifugation in the analysis and purification of spliceosomes assembled In Vitro. In S. Stamm, C. Smith, & R. Lührmann (Eds.), Alternative pre-mRNA splicing: Theory and protocols (pp. 147-153). Weinheim: Wiley-VCH.