The Validity of the Group Investigation Learning Model Documentary Film Media Assisted to Improve Students’ Attitudes of Nationalism. Indonesian Journal of Primary Education, [S. l.], v. 5, n. 2, p. 141–149, 2021. Disponível em: https://ejournal-tasikmalaya.upi.edu/ijpe/article/view/305. Acesso em: 28 sep. 2026.