1. 1. Boyle, G., Renewable energy: power for a sustainable future. 1997: Taylor & Francis.
   2. Leong, K., H. C. Ong, et al. (2016). "An overview on current application of nanofluids in solar thermal collector and its challenges." Renewable and Sustainable Energy Reviews 53: 1092-1105
   3. Kumar, R. and M.A. Rosen, A critical review of photovoltaic–thermal solar collectors for air heating. Applied Energy, 2011. 88(11): p. 3603-3614.
   4. Javadi, F., R. Saidur, and M. Kamalisarvestani, Investigating performance improvement of solar collectors by using nanofluids. Renewable and Sustainable Energy Reviews, 2013. 28: p. 232-245.
   5. Tian, Y. and C.-Y. Zhao, A review of solar collectors and thermal energy storage in solar thermal applications. Applied Energy, 2013. 104: p. 538-553.
   6. Du, B., E. Hu, and M. Kolhe, An experimental platform for heat pipe solar collector testing. Renewable and Sustainable Energy Reviews, 2013. 17: p. 119-125.
   7. Hlaing, S. and M. M. Soe (2012). "Design calculation and heat transfer analysis of heat pipe evacuated tube solar collector for water heating." International Journal of Science, Engineering and Technology Research (IJSETR) 1: 1-5.
   8. http://www.apricus.com/html/solar collector size.htm, 2007.
   9. http://www.sltenergy.com/heat-pipe-manifold/.