M. A. Habib, M. T. Shahadat, N. M. Bahadur, I. M. I. Ismail, and A. J. Mahmood, “Synthesis and characterization of ZnO-TiO2 nanocomposites and their application as photocatalysts”, Int. Nano Lett., vol. 3, no. 1 (December 2013), Jan. 2013, doi: 10.1186/2228-5326-3-5.