Basturkman, H. (1999). A Content Analysis of Elt Textbook Blurbs: Reflections of Theory-in-Use, RELC Journal ; Vol. 30, No. 1; pp. 18-38.
Blaine F. Peden, Sarah E. Hausmann(2000). Data Graphs in Introductory and Upper Level Psychology Textbooks: A Content Analysis. Teaching of Psychology, Vol. 27 (2), pp. 93-97.