Fleming AD, Philip S, Goatman KA, Sharp PF, Olson JA. Automated clarity assessment of retinal images using regionally based structural and statistical measures. Med Eng Phys. 2012 Sep 1;34(7):849-59. doi: 10.1016/j.medengphy.2011.09.027
Phanikumar CV, Maitra B. Willingness-to-pay and preference heterogeneity for rural bus attributes. J Transp Eng A-Syst. 2007 Jan;133(1).