@article{Gittelsohn1997,
author = {Gittelsohn, J. and Shankar, A. V. and West, K. P. and Ram, R. M. and Gynwali, T.},
title= {Estimating Reactivity in Direct Observation Studies of Health Behaviors},
year = {1997},
journal = {Human Organization},
volume = {56},
number = {2},
pages = {182--189},
}