Variational inference for Dirichlet Process mixture models with multinomial mixture components. You can find more information in this report. Based on the following paper:

Blei, D. M., & Jordan, M. I. (2006). Variational inference for Dirichlet process mixtures. Bayesian analysis, 1(1), 121-143. pdf

You can get an example dataset here (2246 documents from the Associated Press, from David Blei).