Pengaruh Promosi dan Kualitas Pelayanan terhadap Kepercayaan dan Loyalitas Donatur Dompet Dhuafa Riau (The Effect of Promotion and Quality of Service on the Trust and Loyalty of Dompet Dhuafa Riau) - Saputra, Andrika (Universitas Islam Negeri Sultan Syarif Kasim Riau, 2020)