You are welcome to download these tests provided that they are used for genuine research purposes, and provided due acknowledgement of ARC as the source is given.
Brayne, (2004) The CAST (Childhood Asperger Syndrome Test) : test accuracy Autism :45-68 F.
Brayne, (2002) The CAST (Childhood Asperger Syndrome Test) : Preliminary development of UK screen for mainstream primary-school children Autism 6(1):9-31 E.
Clubley, (2001) The Autism Spectrum Quotient (AQ) : Evidence from Asperger Syndrome/High Functioning Autism, Males and Females, Scientists and Mathematicians Journal of Autism and Developmental Disorders 31:5-17 C.
Baron-Cohen (2012) Toward Brief "Red Flags" for Autism Screening: The Short Autism Spectrum Quotient and the Short Quantitative Checklist in 1,000 Cases and 3,000 Controls Journal of the American Acad of Child & Adolescent Psychiatry O.