1. Autonomous languages of twins.;Bakker P.;Acta Geneticae Medicae at Gemellologiae,,1987
2. Bawkin H. (1974). Reading disability in twins. Developmental Medicine and Child Neurology 15 184–187.
3. Bentley P. (1988). Speech and language delays in identical twins. Report No. EC 211 260. National College of Education. (ERIC Document Reproduction Service No. ED 300 965).
4. Language disabilities in three twin pairs and their relatives;Osorio M. R. L.,;Acta Geneticae Medicae et Gemellologiae,1985
5. Twin-singleton language differences;Conway D.;Canadian Journal of Behavioral Sciences,1980