Charfi, Ahmed Anis, and Muhammad Atif. 2014. “Virtual Agent: A Determinant of Online Social Presence and Consumer Trust in Websites”. International Journal of Economic Practices and Theories 4 (5):796-806. http://ijept.eu/index.php/ijept/article/view/Virtual_Agent_A_Determinant_of_Online_Social_Presence_and_Cons.