Marszalek, J. M., A. L. Odom, S. M. LaNasa, and S. A. Adler. “Distortion or Clarification: Defining Highly Qualified Teachers and the Relationship Between Certification and Achievement”. Education Policy Analysis Archives, vol. 18, Nov. 2010, p. 27, doi:10.14507/epaa.v18n27.2010.