Rubin, Timothy N. ; Chambers, America ; Smyth, Padhraic ; Steyvers, Mark: Statistical Topic Models for Multi-Label Document Classification, 2011. - cite arxiv:1107.2462
Carpena, P. ; Bernaola-Galván, P. ; Hackenberg, M. ; Coronado, A. V. ; Oliver, J. L.: Level statistics of words: Finding keywords in literary texts and symbolic sequences. In: Physical Review E (Statistical, Nonlinear, and Soft Matter Physics), 79 (2009), Nr. 3, S. 035102