Evaluation of the effectiveness of using the method of "Circle training" and the method of "Distance training" to improve the physical fitness of intensive athletics students at Hanoi University of Physical Education and Sports. (2019). Tạp Chí Khoa học Đào tạo Và Huấn luyện Thể Thao, 1(Đặc biệt), 406. https://tckhupes1.edu.vn/index.php/upes1/article/view/1665