Gaya APA

Hong, T., Koe, T. (2025). New Frontiers 4 : Student book B1 intermediate (Sixth Reprinted). : PT. Asta Ilmu Sukses.

Gaya MLA

Hong, Thomas., Koe, Tapanga. "New Frontiers 4 : Student book B1 intermediate". Sixth Reprinted : PT. Asta Ilmu Sukses, 2025. Text.