@article{Haviland2007,
author = {Haviland, A. and Nagin, D.D. and Rosenbaum, P.R.},
title= {Combining propensity score matching and group-based trajectory analysis in an observational study},
year = {2007},
doi = {10.1037/1082-989X.12.3.247},
journal = {Psychological Methods},
volume = {12},
number = {3},
pages = {247--267},
}