@article{HammerschmidtZeitlerLeidl2003, author = {Thomas Hammerschmidt and H. P. Zeitler and R. Leidl}, title = {Unexpected yes- and no-answering behaviour in the discrete choice approach to elicit willingness to pay: a methodological comparison with payment cards}, journal = {International Journal of Health Care Finance and Economics}, number = {3 / 3}, pages = {147 -- 166}, year = {2003}, }