Li, Z., L. Kong, B. Hui, X. Shang, L. Gao, N. Luan, X. Zhuang, D. Wang, and Z. Bai. “Identification and Antioxidant Activity of Carotenoids from Superfine Powder of Rhodobacter Sphaeroides”. Emirates Journal of Food and Agriculture, vol. 29, no. 11, Oct. 2017, pp. 833-45, doi:10.9755/ejfa.2017.v29.i11.1479.