An Algorithm for Nonparametric Estimation of a Multivariate Mixing Distribution with Applications to Population Pharmacokinetics oleh Walter M. Yamada, Michael N. Neely, Jay Bartroff, David S. Bayard, James V. Burke, Mike van Guilder, Roger W. Jelliffe, Alona Kryshchenko, Robert Leary, Tatiana Tatarinova, Alan Schumitzky