Brubaker L, Richter HE, Barber MD, Hsu Y, Rahn DD, Menefee S, Visco A, Spino C, Martin S, Meikle SF. Pelvic floor disorders clinical trials: participant recruitment and retention. Int Urogynecol J. 2013 Jan 1;24(1):73-9.
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.