Gibbons, L.; Crane, P. K.; Mehta, K. M.; Pedraza, O.; Tang, Y.; Manly, J. J.; Narasimhalu, K.; Teresi, J.; Jones, R. N.; Mungas, D. Multiple, Correlated Covariates Associated With Differential Item Functioning (DIF): Accounting for Language DIF When Education Levels Differ across Languages. Ageing Res 2011, 2, e4.