1. American Speech-Language-Hearing Association. (2010a). ASHA members and others who provide bilingual and Spanish-language services for year end 2009. Retrieved from www.asha.org/uploadedFiles/Demographic-Profile-Bilingual-Spanish-Service-Members.pdf.
2. American Speech-Language-Hearing Association. (2010b). 2010 schools survey: SLP workforce/work conditions. Retrieved from http://www.asha.org/uploadedFiles/Schools10Workforce.pdf.
3. Introduction to item response theory and rasch models for speech-language pathologists;Baylor;American Journal of Speech-Language Pathology,2011
4. Applying the Rasch model: Fundamental measurement in the human sciences;Bond,2007
5. A first language: The early stages;Brown,1973