Rujukan

 Alī Ibn Muḥammad, Al-Jumu‘ah. (2009). Mu’jam al-Muṣṭalahāt alIqtisadiyyah Wa AlIslāmiyyah. Riyadh: Maktabah al-‘Ubaykat. 

Bang, H. & Ross, S. (2009). Volunteer Motivation and Satisfaction. Journal of Venue and Event Management; 1(1): 61-77.

Blomberg, O. (2011). Concepts of Cognition for Cognitive Engineering. International Journal of Aviation Psychology; 21(1): 85-104.

 Brandt, M.J. & Wetherell, G.A. (2012). What Attitudes are Moral Attitudes? The Case of Attitude Heritability. Social Psychological and Personality Science; 3(2): 172-179. 

Chacon, F., Perez, T., Flores, J. & Vecina, L.M. (2011). Motives for Volunteering: Categorization of Volunteers’ Motivations using Open-ended Questions. Psychology in Spain; 15 (1): 48-56