YU, Tao. The Doppler Frequency Shift Formula Derived by Directly Differentiating the Wave Speed Formula. European Journal of Applied Sciences, [S. l.], v. 12, n. 2, p. 78–83, 2024. DOI: 10.14738/aivp.122.16567. Disponível em: https://scholarpublishing.org/journals/index.php/EJAS/article/view/8753. Acesso em: 30 may. 2026.