1. Patent US3369939A, J.H. Myer, 1962.
2. 20 000 PERL Silicon Cells for the ‘1996 World Solar Challenge’ Solar Car Race;Zhao;Progress in Photovoltaics,1997
3. Patent DE3942205A1, J.S. H. Gochermann, 1989.
4. Solar cell efficiency tables (version 46);Green;Progress in Photovoltaics,2015
5. ’Cogenra Wins $2M U.S. Energy Dept. SunShot Award’ in Business wire, 2014, http://www.businesswire.com/news/home/20141022006260/en/Cogenra-Wins-2M-U.S. -Energy-Dept. -SunShot#. VJByRCvF9W-.