1. American Psychological Association, Coalition for Psychology in Schools and Education 2015 Top 20 principles from psychology for preK-12 teaching and learning http://www.apa.org/ed/schools/cpse/top-twenty-principles.pdf
2. Aungst , G. 2014 Using Webb's depth of knowledge to increase rigor https://www.edutopia.org/blog/webbs-depth-knowledge-increase-rigor-gerald-aungst
3. Pedagogical content knowledge: An integrative model for teacher preparation;Cochran;Journal of Teacher Education,1993