Ryan M, Watson V, Amaya-Amaya M. Methodological issues in the monetary valuation of benefits in healthcare. Expert Rev Pharmacoecon Outcomes Res. 2003 Dec;3(6):717-27. doi: 10.1586/14737167.3.6.717
Poulos C, Cahn D, Whittington D, Thoa L, Utomo N, Hoa N. Household demand for typhoid fever vaccines in Hue City, Vietnam: implications for immunization programs. Poster presented at the 4th World Congress of the International Health Economics Association; June 2003.