Primatesta P, Plana Hortoneda E, Rothenbacher D. Gout treatment and comorbidities: a retrospective cohort study in a large US managed care population. BMC Musculoskelet Disord. 2011 May 20;12:103. doi: 10.1186/1471-2474-12-103
Phanikumar CV, Maitra B. Modeling willingness-to-pay values for rural bus attributes under different trip purposes. JTRF. 2006;45(2):31-44. doi: 10.22004/ag.econ.206787