Hughes, J. W. (2007). Environmental problem solving: A how-to guide. University of Vermont Press ; Published by University Press of New England.
Lua i Stíl Chicago (17ú heag.)Hughes, Jeffrey W. Environmental Problem Solving: A How-to Guide. Burlington, VT : Hanover: University of Vermont Press ; Published by University Press of New England, 2007.
Lua MLA (9ú heag.)Hughes, Jeffrey W. Environmental Problem Solving: A How-to Guide. University of Vermont Press ; Published by University Press of New England, 2007.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.