Kerr, J. e. a. (1997). Natural resource economics. Oxford & IBH.
Chicago Style aipamenaKerr, John et al. Natural Resource Economics. New Delhi: Oxford & IBH, 1997.
MLA aipamenaKerr, John et al. Natural Resource Economics. Oxford & IBH, 1997.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.