The IEA study of written composition - Gorman, T. P.; Purves, Alan C. (Alan Carroll), 1931-1996; Degenhart, R. E. (Published for the International Association for the Evaluation of Educational Achievement by Pergamon Press, 1988)
τ.1. xiv, 214 σ. - 1988 – τ.2. ix, 290 σ. - 1992.