Raghunathan K, Layton JB, Ohnuma T, Shaw AD. Observational research using propensity scores. Adv Chronic Kidney Dis. 2016 Nov;23(6):367-72. doi: 10.1053/j.ackd.2016.11.010
Fleming A, Goatman KA, Sharp PF, Styles CJ, Wikes WN, Olson JA. A large scale validation of automated grading. Eur J Ophthalmol. 2009 May 1;19(3):504.
Mansfield CA, Johnson FR, Van Houtven GL. The missing piece: valuing averting behavior for children's ozone exposures. Resour Energy Econ. 2006 Aug;28(3):215-28.
Smith VK, Poulos C, Kim H. Treating open space as an urban amenity. Resour Energy Econ. 2002 Feb 15;24(1-2):107-29.