@article {zhang2008power,
	title = {Power Spectral Analysis of EEG Activity During Sleep in Cigarette Smokers},
	journal = {Chest},
	volume = {133},
	number = {2},
	year = {2008},
	pages = {427{\textendash}432},
	publisher = {Am Coll Chest Phys},
	author = {Zhang, L and Samet, J and Caffo, B and Bankman, I and Punjabi, N}
}
@article {zhang2006cigarette,
	title = {Cigarette smoking and nocturnal sleep architecture},
	journal = {American Journal of Epidemiology},
	volume = {164},
	number = {6},
	year = {2006},
	pages = {529},
	publisher = {Oxford Univ Press},
	author = {Zhang, L and Samet, J and Caffo, B and Punjabi, N}
}
