@article{Pennings:114787,
      author = {Pennings, Joost M.E. and Garcia, Philip and Irwin, Scott  H.},
      title = {{Accounting for Heterogeneity in Hedging Behavior:  Comparing & Evaluating Grouping Methods}},
      pages = {1. - 13},
      month = {Aug},
      year = {2011},
}