1. American Institute of Physics. 1998. Children’s Misconceptions About Science. http://amasci.com/miscon/opphys.html
2. Atherton, J. S. 2009. Learning and Teaching: Piaget's Developmental Theory. http://www.learningandteaching.info/learning/piaget.htm
3. BERA [British Educational Research Association]. 2011. Ethical Guidelines for Educational Research. http://www.bera.ac.uk/wp-content/uploads/2014/02/BERA-Ethical-Guidelines-2011.pdf