@article{Ai2003,
author = {Ai, C. and Norton, E.C.},
title= {Interaction terms in logit and probit models},
year = {2003},
doi = {10.1016/S0165-1765(03)00032-6},
journal = {Economics Letters},
volume = {80},
number = {1},
pages = {123--129},
}