To cite use:

  Matt Taddy (AISTATS 2012) On Estimation of Topic Models,
  http://jmlr.csail.mit.edu/proceedings/papers/v22/taddy12/taddy12.pdf

A BibTeX entry for LaTeX users is

  @InProceedings{,
    title = {On Estimation for Topic Models},
    author = {Matt Taddy},
    year = {2012},
    booktitle = {AISTATS},
    note = {http://jmlr.csail.mit.edu/proceedings/papers/v22/taddy12/taddy12.pdf},
  }