1. Academy of Medicine Singapore, Ministry of Health Clinical Practice Guidelines Workgroup on Autism Spectrum Disorders. (2010). Academy of Medicine Singapore-Ministry of Health clinical practice guidelines: Autism Spectrum Disorders in pre-school children. Singapore Medical Journal, 51(3), 255–263.
2. AGREE Collaboration. (2003). Development and validation of an international appraisal instrument for assessing the quality of clinical practice guidelines: the AGREE project. Quality and Safety in Health Care, 2, 18–23.
3. American Academy of Paediatrics. (2011). Policy statement—AAP publications reaffirmed and retired. Pediatrics, 127(3), E857.
4. Baird, G., Charman, T., Pickles, A., Chandler, S., Lucas, T., Meldrum, D., et al. (2008). Regression, developmental trajectory and associated problems in disorders in the autism spectrum: the SNAP study. Journal of Autism and Developmental Disorders, 38, 1827–1836.
5. Baird, G., Simonoff, E., Pickles, A., Chandler, S., Loucas, T., Meldrum, D., et al. (2006). Prevalence of disorders of the autism spectrum in a population cohort of children in South Thames: The Special Needs and Autism Project (SNAP). Lancet, 368(9531), 210–215.