Dixon, D. R., Tarbox, J., Najdowski, A. C., Wilke, A. E., & Granpeesheh, D. (2011). A comprehensive evaluation of language for early behavioral intervention programs: The reliability of the SKILLS Language Index. Research in Autism Spectrum Disorders, 5(1), 506–511. https://doi.org/10.1016/j.rasd.2010.06.016