Bouhali, M., and omar labani. “The Axtent to Which the Criterion of Necessity Is Used in Investment decision Assesement in Cmpany: The Company of Industrial Pipe ALFAPIPE Ghardaia As a Model”. Dirassat Journal Economic Issue, Vol. 9, no. 2, June 2018, pp. 101-14, doi:10.34118/djei.v9i2.147.