@article {JoGu2008statmed,
	title = {Use of instrumental variables in the analysis of generalized linear models in the presence of unmeasured confounding with applications to epidemiological research},
	journal = {Statistics in Medicine},
	volume = {27},
	year = {2008},
	pages = {1539-1556},
	doi = {10.1002/sim.3036},
	author = {Johnston, K. and Gustafson, P. and Levy, A. R. and Grootendorst, P.}
}
