NAYELY LEYVA-LÓPEZA, et al. “Optimized Enzyme-Aided Extraction Enhances Recovery of Carotenoids from Tomato Peel and Improves the Biological Activity”. International Journal of Pharma and Bio Sciences, vol. 8, no. 1, Mar. 2017, pp. 721-7, doi:10.22376/ijpbs.2017.8.1.b721-727.