Gaya APA
Altaf, M, A. et al (1992).
Willingness to Pay for Water in Rural Punjab, Pakistan .
Washington DC:
UNDP-World Bank Water and Sanitation Program.
Gaya MLA
Altaf, Mir, Anjum. et al.
"Willingness to Pay for Water in Rural Punjab, Pakistan".
Washington DC:
UNDP-World Bank Water and Sanitation Program,
1992.
print.