Field, B. C. (2008). Natural resources economics an introduction second edition. Waveland Press.
Lua i Stíl Chicago (17ú heag.)Field, Barry C. Natural Resources Economics an Introduction Second Edition. Waveland Press, 2008.
Lua MLA (8ú heag.)Field, Barry C. Natural Resources Economics an Introduction Second Edition. Waveland Press, 2008.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.