@article {635581,
	title = {Frequency-doubling effect in acoustic reflection by a nonlinear, architected rotating-square metasurface},
	journal = {Physical Review E},
	volume = {99},
	year = {2019},
	pages = {052209},
	author = {Xinxin Guo and Vitalyi E. Gusev and Vincent Tournat and Bolei Deng and Katia Bertoldi}
}
