1. Renewable portfolio standards: a factual introduction to experience from the United States;Wiser,2007
2. Emerging markets for renewable energy certificates: opportunities and challenges;Holt,2005
3. Status and trends in U.S. compliance and voluntary renewable energy certificate markets;Heeter,2011
4. U.S. Department of Energy. Database of state incentive for renewable and efficiency (DSIRE) solar (see also 〈http://www.dsireusa.org/solar/solarpolicyguide/?id=21〉).
5. Renewable Energy Certificate System International. Review of the RES directive (see also 〈http://www.recs.org/target-compliance-market/review-of-the-res-directive〉).