Study the effect of position on the time of astronomical twilight. Baghdad Science Journal, Iraq, Baghdad, v. 6, n. 4, p. 797–803, 2009. DOI: 10.21123/bsj.2009.11887. Disponível em: https://bsj.uobaghdad.edu.iq/index.php/BSJ/article/view/11887.. Acesso em: 19 dec. 2024.