٢٢١- White, S. H. "١٩٧٠": The learning theory tradition and child Psychology. "In" P. H. Mussen "Ed" Carmichael.htm's manual of child Psychology. New York: Wiley.
٢٢٢- Wohlwill, J. F. "١٩٧٣"; The study of behavior development. New York: Academic Press.
٢٢٣- Zeaman, D. & House, B. J. "١٩٦٣"; The role of attention in retardate discrimination Learning. "In" N. R. Ellis "Ed.", Handbook of mental deficiency. New York: Mc Graw- Hill.
٢٢٤- Zigler, E. "١٩٦٣": Met theoretical issues in developmental Psychology. "In" M. H. Marx "Ed."; Theories in contemporary Psychology. New York: Macmillan.