@article{Puhani2012,
author = {Puhani, P.A.},
title= {The treatment effect, the cross difference, and the interaction term in nonlinear ‘difference-in-differences’ models},
year = {2012},
doi = {10.1016/j.econlet.2011.11.025},
volume = {115},
number = {1},
pages = {85--87},
}