Prastiwi, Sosio. 2019. “Pengaruh Marketing Mix Terhadap Loyalitas Konsumen J&C Cookies Di Surabaya”. Yos Soedarso Economic Journal (YEJ) 1 (3):26-34. https://ejurnal.uniyos.ac.id/index.php/ysej-server/article/view/YEJ-1304.