1. https://www.pv-magazine.com/2019/08/20/polysilicon-prices-to-rebound-in-september/.
2. http://www.pvmagazine.com/news/details/beitrag/ first-solar-sets-new-cadmiumtelluride-thin-film-cell-efficiency-record-at-22.1_100023341/.
3. http://www.renewableenergyworld.com/rea/blog/post/ 2014/03/two-thin-film-solar-efficiency-recordsbro ken-this-week?cmpid=WNL-Wednesday-March5-2014.
4. http://www.businesswire.com/news/home/2013040-9006059/en/Solar-Sets-CdTe-Module-Efficiency-World-Record. Accessed 2013.
5. https://www.ise.fraunhofer.de/content/dam/ise/de/ documents/publications/studies/Photovoltaics-Report.pdf/.