United Nations Environment Programme (UNEP) has published some freely available research reports worth adding to your collections. UNEP works collaboratively to promote the wise use and sustainable development of the global environment. This recent report is called Towards a Green Economy: Pathways to Sustainable Developmentand Poverty Eradication – A Synthesis for Policy Makers, which can be viewed online, searched, downloaded, viewed on a mobile device and shared. There are numerous others available here. There are numerous other reports available here.