Fortin Morales, A. M., F. J. R. van de Vijver, and Y. H. Poortinga. “Differential Item Functioning and Educational Risk Factors in Guatemalan Reading Assessment”. Revista Interamericana De Psicología/Interamerican Journal of Psychology, vol. 47, no. 3, Oct. 2014, doi:10.30849/rip/ijp.v47i3.236.