BARRIENTOS, N. E. G.; GÓMEZ, R. F. Didactic material for preparation observation and estimation content on subject recreational activities in nature. International journal of life sciences & earth sciences, [S. l.], v. 3, n. 1, p. 15-19, 2020. DOI: 10.31295/ijle.v3n1.140. Disponível em: https://sloap.org/journal/index.php/ijle/article/view/140. Acesso em: 15 jun. 2021.