ATENA, Rivera. Flexibility and Adaptability of Secondary School Managers to 21st Century Skills. International Journal of Sciences: Basic and Applied Research (IJSBAR), Jordan, v. 40, n. 2, p. 169–185, 2018. Disponível em: https://www.gssrr.org/JournalOfBasicAndApplied/article/view/9123. Acesso em: 13 sep. 2025.