1. Special Education Department, Faculty of Human Development, Universiti Pendidikan Sultan Idris, Tanjung Malim, Perak, Malaysia
2. National Child Development Research Centre, Universiti Pendidikan Sultan Idris, Tanjung Malim, Perak, Malaysia
3. Centre for Disability Research and Policy, Faculty of Medicine and Health, University of Sydney, Camperdown, Australia
4. Educational Studies Department, Faculty of Human Development, Universiti Pendidikan Sultan Idris, Tanjung Malim, Perak, Malaysia