1. Economic costs and benefits of early intervention;Barnett,1990
2. Perspectives on general system theory;Bertalanffy,1975
3. Mental subnormality in the community: A clinical and epidemiological study;Birch,1970
4. Prevention-oriented infant education programs;Bryant;Journal of Children in Contemporary Society,1987
5. Ready to learn: A mandate for the Nation;Carnegie Foundation for the Advancement of Teaching,1991