.Conrad, J. M., & .Clark, C. W. (1987). Natural resource economics: Notes and problems. Cambridge University Press.
Chicago-čujuhus (17. p.).Conrad, Jon M., juo Colin W. .Clark. Natural Resource Economics: Notes and Problems. [Cambridge [Cambridgeshire ; New York: Cambridge University Press, 1987.
MLA-čujuhus (9. p.).Conrad, Jon M., juo Colin W. .Clark. Natural Resource Economics: Notes and Problems. Cambridge University Press, 1987.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.