id	author	title	date	pages	extension	mime	words	sentence	flesch	summary	cache	txt
ejde-418	Sremr, Jiri	Parameter-dependent periodic problems for non-autonomous Duffing equations with sign-changing forcing term	2023	23	.pdf	application/pdf	10802	678	81	[6] X. Han, Y. He, H. Wei; Existence of positive periodic solutions for a nonlinear system of second-order ordinary differential equations, Electron. [14] J. Šremr; Bifurcation of positive periodic solutions to non-autonomous undamped duffing equations, Math.	cache/ejde-418.pdf	txt/ejde-418.txt