Obioma,H, Onyeaghala,. “Servqual Model As Performance Evaluation Instrument for Small and Medium Sized Enterprises (SME): Evidence From Customers in Nigeria”. European Scientific Journal, ESJ 12, no. 28 (October 31, 2016): 520. Accessed April 14, 2024. https://eujournal.org/index.php/esj/article/view/8194.