Hajar. 2021. “Peningkatan Kemampuan Memahami Struktur Kalimat If Condtioanal Bahasa Inggris Melalui Penerapan Model Pembelajaran Kooperatif Tipe Greeting and Sending Problems”. Jurnal Kinerja Kependidikan (JKK): Facilities of Educator Career and Educational Scientific Information 1 (1):31-44. https://journalserambi.org/index.php/jkk/article/view/30.