@article {fonda2013periodic,
	title = {Periodic bouncing solutions for nonlinear impact oscillators},
	journal = {Advanced Nonlinear Studies},
	volume = {13},
	number = {1},
	year = {2013},
	pages = {179{\textendash}189},
	publisher = {Advanced Nonlinear Studies, Inc.},
	doi = {10.1515/ans-2013-0110},
	author = {Alessandro Fonda and Andrea Sfecci}
}
