Phanikumar CV, Maitra B. Willingness-to-pay and preference heterogeneity for rural bus attributes. J Transp Eng A-Syst. 2007 Jan;133(1).
Derby CA, Araujo AB, Johannes CB, Feldman HA, McKinlay JB. Measurement of erectile dysfunction in population-based studies: the use of a single question self-assessment in the Massachusetts Male Aging Study. Int J Impot Res. 2000 Aug 1;12(4):197-204.
Richards EJ, Chao S, Vongs A, Yang J. Characterization of Arabidopsis thaliana telomeres isolated in yeast. Nucleic Acid Res. 1992 Aug 11;20(15):4039-46.