“Pengaruh Promosi Penjualan Dan Kualitas Layanan Terhadap Loyalitas Pelanggan Guardian Health & Beauty Retail”. Jurnal Manajemen dan Bisnis Madani 2, no. 2 (April 28, 2021). Accessed February 21, 2026. https://journal.paramadina.ac.id/index.php/madani/article/view/341.