@article {67005,
	title = {A polynomial-time approximation scheme for the two machine flow shop problem with several availability constraints},
	journal = {Optimization LettersOptimization Letters},
	volume = {6},
	year = {2012},
	month = {2012},
	pages = {559-569},
	isbn = {1862-4480},
	author = {Hadda, Hatem}
}
