To cite softImpute in publication use:

Mazumder R, Hastie T, Tibshirani R (2010). “Spectral Regularization Algorithms for Learning Large Incomplete Matrices.” Journal of Machine Learning Research, 11, 2287–2322.

Hastie T, Mazumder R, Lee J, Zadeh R (2015). “Matrix Completion and Low-rank SVD via Fast Alternating Least Squares.” Journal of Machine Learning Research, 16, 3367–3402.

Corresponding BibTeX entries:

  @Article{,
    title = {Spectral Regularization Algorithms for Learning Large
      Incomplete Matrices},
    author = {Rahul Mazumder and Trevor Hastie and Robert Tibshirani},
    journal = {Journal of Machine Learning Research},
    year = {2010},
    volume = {11},
    pages = {2287--2322},
  }

  @Article{,
    title = {Matrix Completion and Low-rank {SVD} via Fast Alternating
      Least Squares},
    author = {Trevor Hastie and Rahul Mazumder and Jason Lee and Reza
      Zadeh},
    journal = {Journal of Machine Learning Research},
    volume = {16},
    pages = {3367--3402},
    year = {2015},
  }