@article{Haydon2012,
author = {Haydon, A.A. and Herring, A.H. and Halpern, Prinstein, M.J. and Halpern, C.T.},
title= {Beyond age at first sex: Patterns of emerging sexual behavior in adolescence and young adulthood},
year = {2012},
doi = {10.1016/j.jadohealth.2011.09.006},
volume = {50},
number = {5},
pages = {456--463},
}