Sturmer T, Rothman KJ, Avorn J, Glynn RJ. Treatment effects in the presence of unmeasured confounding: dealing with observations in the tails of the propensity score distribution—A simulation study. Am J Epidemiol. 2010 Oct 17;172(7):843-54.
Goyal RK, Patel JG, Sansgiry SS. Pharmacists perceptions of drug reimbursement rates and processing times among managed care plans. Drug benefit trends: a publication for manager and health professionals in hmos and ppos. 2010;22(4):116-20.