SINGH, Ramgopal. विश्व की भाषाओ का वर्गीकरण: २. Vidyapith (વિદ્યાપીઠ), [S. l.], v. 33, n. 1, p. 37–52, 1995. Disponível em: https://journal.gujaratvidyapith.org/index.php/vp/article/view/677. Acesso em: 28 jul. 2026.