“The Impact of Customer Contact Type According to CCM Model on the Operational Efficiency of the System Providing the Service” (2021) Journal of Al-Rafidain University College For Sciences ( Print ISSN: 1681-6870 ,Online ISSN: 2790-2293 ), 39(1), pp. 150–177. doi:10.55562/jrucs.v39i1.210.