Antony J. Willingness to Pay for Access to Improved and Reliable Piped Water: A Contingent Valuation Study in Kerala, India. Thail. Stat. [Internet]. 2018 Dec. 27 [cited 2024 May 3];17(1):75-83. Available from: https://ph02.tci-thaijo.org/index.php/thaistat/article/view/163198