TAUFIQ, Wahyu; MANDARANI, Vidya. Buku Ajar Let’s Learn English Progressively. Umsida Press, [S. l.], p. 1–157, 2021. DOI: 10.21070/2017/978-979-3401-72-0. Disponível em: https://press.umsida.ac.id/index.php/umsidapress/article/view/978-979-3401-72-0. Acesso em: 5 jul. 2025.