Sinambela, Ella Anastasya, and Elis Tika Aprilianti. “Strategi Mengatasi Erosi Loyalitas Pelanggan Di Tengah Intensitas Persaingan Pasar”. Jurnal Ekonomi Dan Bisnis, vol. 1, no. 2, July 2011, pp. 76-89, https://ebis-jurnal.unsuri.ac.id/index.php/ebis/article/view/142.