1. USDA-NRCS (United States Department of Agriculture, Natural Resources Conservation Service), in: Land Resource Regions and Major Land Resource Areas of the United States, the Caribbean, and the Pacific Basin, USDA Handbook 296, 2006. Accessed at: .
2. Soil carbon sequestration impacts on global climate change and food security;Lal;Science,2004
3. IPCC (Intergovernmental Panel on Climate Change), Climate change 2014: synthesis report, in: R.K. Pachauri, L.A. Meyer (core writing team) (Eds.), Contribution of Working Groups I, II and III to the Fifth Assessment Report of the IPCC, IPCC, Geneva, Switzerland, 2015, 151 pp.
4. US-EPA (Environmental Protection Agency), 2018. in: Inventory of U.S. Greenhouse Gas Emissions and Sinks, 1990–2016, US-EPA 430-R-18-003.
5. Summary for policymakers;IPCC,2007