1. 1. Teodorita Al Seadi, DominikRutz, Heinz Prassl, Michael Köttner, Tobias Finsterwalder,Silke Volk, Rainer Janssen. Biogas Handbook, p 10, Oct 2008.
   2. Jie Zhou, Shubiao Wu, Wanqin Zhang, Changle Pang,Baozhi Wang,Renjie Dong, Li Chen , “A Comprehensive Model for Evaluation of Carbon Footprint and Greenhouse Gages Emission in Household Biogas Plants” pp 1-2, 2012 [3] http://teeic.indianaffairs.gov/er/carbon/carboninfo/redu ce/index.htm, Mar 2016
   3. Central Statistics Office Ministry of Statistics And Programme Implementation Government Of India New Delhi ,“Energy Statistics”,pp 4-5, 2015.
   4. http://www.biogas-renewable-energy.info/Feb2016
   5. Subrata Bose (Member Secretary, NCDMA, MoEF&CC) Enrico Rubertus (GIZ), Kundan Burnwal (GIZ),Ashish Chaturvedi (GIZ), Santosh Kumar Singh (GIZ), Inderjeet Singh (PWC), Prashant Vikram Singh (PWC), “Carbon Market Roadmap for India, Federal Ministry for the Environment, Nature Conservation Building and Nuclear Safety”, pp 1-2, Jan 2014.
   6.  Michael Gillenwater, Stephen Seres, “The Clean Development Mechanism: A Review of the First International Offset Program”, pp 4-7, March 2011.
   7.  Yuvika Gupta “Carbon Credit: A Step Towards Green Environment”, Global Journal of Management and Business Research, Vol. 11, Issue 5 Version 1.0, pp 17-18, Apr 2011.
   8.  H. Pathak, N. Jain, A. Bhatia, S. Mohanty, Navindu Gupta. “Global warming mitigation potential of biogas plants in India”, Environ Monit Assess, pp3-6, 2009.
   9.  “Akshay Urja”, A bi-monthly newsletter of the ministry of New and Renewable Energy, Government of India, pp 38-40, vol. 5 Issue 6, June 2012
   10. http://www.carbon-calculator.org.uk/Mar2016
   11. Bhushan Ramesh Shende and Rajnikant S. Jadhao, “Carbon Credit Science and Business”, Scientific Reviews And Chemical Communications, pp 84-86, May 2014.