1. Preschool Education Program, issued under Circular No. 17/2009/ TT-BGDĐT and Circular No. 01/VBHN-BGDĐT, dated January 24, 2017 (2009).
2. Dương Diệu Hoa 2008 Developmental Psychology, Hanoi National University of Education Publishing House.
3. Jang Young Soog 2009 Guiding Exploration Activities of the Surrounding Environment for Preschool Children, Education Publishing House, Hanoi.
4. David W., Penny C. 2008 Teaching and Learning in the Early Years, Third Edition.
5. Dostál, J. 2015 Theory of Problem Solving, Procedia-Social and Behavioral Sciences, 174, 2798-2805.
6. Duncker, K. 1945 On Problem-Solving, Psychological Monographs, No. 270.
7. Foster, S. L., & Crain, M. M. 2004, Social Skills and Problem-Solving Training, Comprehensive Handbook of Psychotherapy, Cognitive-Behavioral Approaches, 2, 31.
8. Current Status of Science Education for 5-6-Year-Olds in Some Public Preschools in Central Vietnam, in: Hungarian Educational Research Journal, Volume 11, Issue 4 2021.