@article {1006606,
	title = {Designing steep, sharp patterns on uniformly ion-bombarded surfaces},
	journal = {Proceedings of the National Academy of Sciences},
	volume = {113},
	number = {41},
	year = {2016},
	author = {Perkinson, Joy C. and Michael J. Aziz and Michael P. Brenner and Miranda Holmes-Cerfon}
}
