@article {64937,
	title = {On the optimality conditions of the two-machine flow shop problem},
	journal = {European Journal of Operational ResearchEuropean Journal of Operational Research},
	volume = {266},
	year = {2018},
	month = {2018},
	pages = {426-435},
	isbn = {0377-2217},
	author = {Hadda, Hatem and Dridi, Najoua and Hajji, Mohamed Karim}
}
