F. Djaafar and  B. Hadri and  G. Bachir,  Comparison between the Efficiency of Heterojunction Thin Film InGaP\GaAs\Ge and InGaP\GaAs Solar Cell.   journal   = {International Journal of Energy and Power Engineering}, [online]. World Academy of Science, Engineering and Technology.
    March 2017, vol. 123(3). 327 - 331
    [viewed 08 December 2019]. Available from: https://publications.waset.org/pdf/10006842.