WU, C. . A study of language varieties in once upon a time in America from the perspective of sociolinguistics. American Journal of Social Sciences and Humanities, [S. l.], v. 10, n. 2, p. 125–139, 2025. DOI: 10.55284/ajssh.v10i2.1684. Disponível em: https://mail.onlinesciencepublishing.com/index.php/ajssh/article/view/1684. Acesso em: 24 dec. 2025.