@article {agarwal2003nonoscillatory,
	title = {Nonoscillatory criteria for singular higher order differential equations},
	journal = {Aequationes mathematicae},
	volume = {66},
	year = {2003},
	note = {n/a},
	pages = {180{\textendash}190},
	publisher = {Springer International Publishing},
	abstract = {n/a},
	author = {Agarwal, Ravi P and Said R. Grace and O{\textquoteright}Regan, Donal}
}
