@article {pmid22241689,
	title = {Mixed effect Poisson log-linear models for clinical and epidemiological sleep hypnogram data},
	journal = {Stat Med},
	volume = {31},
	number = {9},
	year = {2012},
	month = {Apr},
	pages = {855{\textendash}870},
	author = {Swihart, B and Caffo, B and Crainiceanu, C and Punjabi, N.M.}
}
@article {swihartTransition,
	title = {Models of sleep hypnograms scalable to epidemiological studies},
	journal = {Tentatively accepted in Statistics in Medicine},
	year = {2012},
	author = {Swihart, B and Caffo, B and Crainiceanu, C and Punjabi, N}
}
