Aaker, D., Kumar, V. (2019). Marketing research. (13 th Edition). John Wiley & Sons. Ali, A. E. M., Hamad, M. A. A., Abdallh, M. A. A., and Elagab, M. A. M. (2020). The role of extension officers in delivering agricultural services to the small-scale farmers, Gezira State, Sudan. American International Journal of Agricultural Studies, 3(1), 51-65. Arayesh, Bagher (2011). An Investigation and Prioritize of Farm Consultants Project Problems from the View Point of Farmers (Case Study: Ilam, Iran). Australian Journal of Basic & Applied Sciences. 2011, Vol. 5 Issue 6, p1341-1343. 3p. 1 Cha. Davidson, p. a, Ahmad, M., Ali, T. (2011). Dilemmas of agricultural extension in Pakistan: food for thought. Agricultural Research and Extension Network.Network Paper, No.116, Retrieved from: www.odi.org.uk/agren/publist.html. Faure, G. Yann Desjeux & Pierre Gasselin (2012). New Challenges in Agricultural Advisory Services from a Research Perspective: A Literature Review, Synthesis and Research Agenda, The Journal of Agricultural Education and Extension, 18:5, 461-492. http://dx.doi.org/10.1080/1389224X.2012.707063. Ghorbani, M. (2008). Evaluation of Agricultural Advisory Services Effects on Sugar Beet in Rzavi Khorasan Province.Journal of Applied Sciences, 8(20). Moumeni H. (2011). Evaluating Rice Supervisor Extensionists' Performance: The Case Study of Mazandaran Province, Iran. American-Eurasian Journal of Agricultural & Environmental Sciences. Volume 11 Number 1. 38-44. O'Neill, B. (2010). Obtaining High-Quality, "Low-Maintenance" Stakeholder Input: How to Create a Virtual Statewide Extension Program Advisory Committee, Journal of Extension, 48, 2. Samuel Benin, Ephraim Nkonya, Geresom Okecho, Joseé Randriamamonjy, Edward Kato, Geofrey Lubade and Miriam Kyotalimye. (2011). Returns to spending on agricultural extension: the case of the National Agricultural Advisory Services (NAADS) program of Uganda. Agricultural Economics. 42(2): 249–267.