Nurmakhanov Б. and Bektibaeva Z.K. Б.З. 2023. On one method for determining the number and plan of natural experiments. Рroblems of engineering and professional education. 12, 2 (Mar. 2023), 53–57. DOI:https://doi.org/10.32523/2220-685X-2012-12-2-53-57.