IBRAHIM, Motasim Hashim. Measuring and tracking the rate of time flow according to the laws of relativity, in form of the analog clock - spacetime clock model. Journal of natural sciences, life and applied sciences, New Mexico, United States, v. 6, n. 3, p. 115–143, 2022. DOI: 10.26389/AJSRP.S030822. Disponível em: https://ajsrp.ojsexpert.com/index.php/jnslas/article/view/5617. Acesso em: 19 dec. 2025.