I. . Dubrovskyi and V. Bucharskyi, “Statement of the problem of designing a liquid rocket engine dual bell nozzle of the maximum thrust using the direct method of the calculus of variations”, Chall. issue mod. sci., vol. 1, pp. 22–28, Jun. 2023, Accessed: Dec. 22, 2024. [Online]. Available: https://cims.fti.dp.ua/j/article/view/6