@article{Bell2015,
author = {Bell, A.  and Jones, K. },
title= {Explaining fixed effects: Random effects modeling of time-series cross-sectional and panel data},
year = {2015},
doi = {10.1017/psrm.2014.7},
journal = {Political Science Research and Methods },
volume = {3},
number = {1},
pages = {133--153},
}