1. Bankson, N. W. & Bernthal, J. E. (1990). Bank-son-Bernthal test of phonology . Austin, TX: Pro-Ed.
2. Calder, H. (1992). Reading freedom teacher's manual. NSW, Australia: Pascal Press.
3. Developmental apraxia of speech: Determiners of differential diagnosis
4. Dodd, B., Crosbie, S., MacIntosh, B., Teitzel, T. & Ozanne, A. (2000). Preschool and primary inventory of phonological awareness (PIPA). London, UK: Psychological Corporation.