1. Philippe F X, Nicks B. Review on greenhouse gas emissions from pig houses: production of carbon dioxide, methane and nitrous oxide by animals and manure. Agriculture, Ecosystems & Environment, 2015, 199(0): 10–25
2. World Livestock F A O. 2011–Livestock in Food Security. Rome 2011. Available online at http://www.fao.org/docrep/014/i2373e/i2373e.pdf (accessed January 18, 2017)
3. Pigs F A O. Available online at http://www.fao.org/ag/againfo/themes/en/pigs/home.html (accessed March 11, 2016)
4. FAO. FAOSTAT 2013. Available online at http://faostat.fao.org/site/573/default.aspx#ancor(accessed September 7, 2016)
5. European Commission. EU Climate Action: Key targets for 2030. Available online at http://ec.europa.eu/clima/citizens/eu_en (accessed January 18, 2017)