Gard, A., Gilman, L., & Gorman, J. (n.d.). Speech and Language Development Chart [Chart]. In Pro-Ed (2nd ed., pp. 1-9). Owens, R. (2016). Language Development, An Introduction, 9th Edition. Boston: Pearson Education, Inc.
Hobek, A. (2016). Lectures from CSD-3011 Speech and Language Development, Communication and Sciences Department, University of Cincinnati. Many lectures adapted from Owens, R. (2016). Language Development, An Introduction, 9th Edition. Boston: Pearson Education, Inc.
Owens, R. (2016). Language Development, An Introduction, 9th Edition. Boston: Pearson Education, Inc.
Shah, A. (n.d.). Semantic Development: Learning the meaning of words. Retrieved April 20, 2017, from http://academic.csuohio.edu/shah_a/week4.html
Your Child's Communication Development. (n.d.). Retrieved April 20, 2017, from http://www.asha.org/public/speech/development/communicationdevelopment/