Conceptual and statistical issues in contingent valuation :  estimating the value of altered visibility in the Grand Canyon / 
Daniel S. Levy ... [et al.]. 
 - Santa Monica, CA :  Rand Corp.,  1995. 
 - xv, 39 p. :  ill. ;  28 cm. 
<br/><br/> 'MR-344-RC'--Cover. 
<br/><br/>Includes bibliographical references (p. 35-39). 
<br/><br/><label>ISBN: </label>0833015001 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Air--Pollution--Economic aspects--Statistical methods.--Arizona--Grand Canyon<br/>Contingent valuation.