@book {agarwal2013oscillation,
	title = {Oscillation theory for difference and functional differential equations},
	year = {2013},
	note = {n/a},
	publisher = {Springer Science \& Business Media},
	organization = {Springer Science \& Business Media},
	abstract = {n/a},
	author = {Agarwal, Ravi P and Said R. Grace and O{\textquoteright}regan, Donal}
}
