@TechReport{economics.dp.2009-9,
 author = {Cogoy, Mario},
 title = {A Model of Eco-Efficiency and Recycling},
 type = {Economics Discussion Paper},
 institution = {Kiel Institute for the World Economy},
 year = {2009},
 number = {2009-9},
 url = {http://www.economics-ejournal.org/economics/discussionpapers/2009-9}
}