NORTHERN PINGHUA PROFICIENCY AMONG HERITAGE SPEAKERS: INFLUENCING FACTORS IN A MULTILINGUAL CHINESE CONTEXT. Quantum Journal of Social Sciences and Humanities, [S. l.], v. 6, n. 4, p. 239–254, 2025. DOI: 10.55197/qjssh.v6i4.732. Disponível em: https://www.qjssh.com/index.php/qjssh/article/view/732. Acesso em: 5 jul. 2026.