Oyedeji  Oluwatimilehin Samuel, “Development of a real estate agency management system”, < https://www.academia.edu/16317840/Development_of_a_real_estate_agency_management_system_Ilorin_as_a_case_study>, 2013, (14/10/2019).

Y.K. Almoayyed, “About us: Creating land marks and history”, < http://almoayyedproperties.com/?page_id=1126 >, 2014, (14/10/2019).

Penna Sparrow, “Waterfall model of SDLC”, <https://www.ianswer4u.com/2011/11/waterfall-model.html >, 2012, (14/10/2019).