@article {6361,
	title = {Instabilities and sound speed of a Bose-Einstein condensate in the Kronig-Penney potential},
	journal = {Laser Physics},
	year = {2007},
	pages = {190-197},
	doi = {10.1134/S1054660X07020247},
	author = {Xi Dong and Biao Wu}
}
