@article {10133,
	title = {Spontaneous scroll ring creation and scroll instability in oscillatory medium with gradients},
	journal = {Physical Review E - Statistical, Nonlinear, and Soft Matter Physics},
	year = {2005},
	doi = {10.1103/PhysRevE.72.066207},
	author = {Chen Wang and Shen Wang and Chunxia Zhang and Qi Ouyang}
}
