Wagner, R.K., & Torgesen, J.K.(1987).The nature of phonological processing and its causal role in the acquisition of reading skills.Psychological Bulletin, 101, 192-212.
Wagner, R., Torgesen, J., Rashotte, C.A, Hecht, S., Barker, T., Burgess, T., et al.(1997).Changing relations between phonological processing abilities and word-level reading as children develop from beginning to skilled readers: A 5-year longitudinal study.Developmental Psychology, 33, 468-479.