1. Rozhkov M.I., Conceptual Ideas, Works, Students (Yaroslavl, Yaroslavl State Pedagogical University named after K.D. Ushinsky, 2016)
2. Zhulyabina N.M., Additional education of children abroad: understanding, politics, regulation. Series Modern Education Analytics, 9(17) (NRU HSE, Moscow, 2017). https://ioe.hse.ru/data/2018/02/07/1162172500/%aD0%A1%aD0%90%D00/o9E_90/o2817%29_%D1%8D%D0%BB%D0%B5%D0%BA%D1%82%D1%80%D0%BE%D0%BD%D0%BD%D1%8B%D0%B9.pdf
3. Saqib N.U., Abdul Raheem M., Iqbal M., Salman M., Shahzad T., Effects of Extracurricular Activities on Students (Department of Electrical Engineering College of Electrical and Mechanical Engineering, National University of Sciences and Technology, January 2018)
4. Freeman R., The Relationship Between Extracurricular Activities and Academic Achievement. Submitted in partial fulfillment of the requirements of Doctor of Education at National Louis University National College of Education, National Louis University, Chicago (2017). https://digitalcommons.nl.edu/diss/245
5. Braden T., The BYU Undergraduate Journal in Psychology, 12(2), Art. 14 (2017). https://scholarsarchive.byu.edu/intuition/vol12/iss2/14