Berry، Leonard L. (2002). "Relationship Marketing of Services Perspectives from 1983 and 2000". Journal of Relationship Marketing. ج. 1 ع. 1: 59–77. DOI:10.1300/j366v01n01_05. ISSN:1533-2667.
Berry، Leonard L. (2002). "Relationship Marketing of Services Perspectives from 1983 and 2000". Journal of Relationship Marketing. ج. 1 ع. 1: 59–77. DOI:10.1300/j366v01n01_05. ISSN:1533-2667.