@article{Preacher2008,
author = {Preacher, K.J. and Hayes, A.F.},
title= {Asymptotic and resampling strategies for assessing and comparing indirect effects in multiple mediator models},
year = {2008},
doi = {10.3758/BRM.40.3.879},
journal = {Behavior Research Methods},
volume = {40},
number = {3},
pages = {879--891},
}