Hariyadi, A. et al. 2017. Combination of Dragon Fruit, Hibiscus and Bitterleaf as Dye Sensitizer to Increase Efficiency of DSSC. International Journal on Advanced Science, Engineering and Information Technology. 7, 3 (Jun. 2017), 936–942. DOI:https://doi.org/10.18517/ijaseit.7.3.2445.