Ma’rifah, U., P. Raja, and F. Flora. “Modified PPP Procedure in Teaching Conditional Sentences Through Whatsapp for Vocational School Students”. QALAMUNA: Jurnal Pendidikan, Sosial, Dan Agama, Vol. 14, no. 1, June 2022, pp. 133-52, doi:10.37680/qalamuna.v14i1.1462.