C S Castañeda, P J Almanza-Merchán, E H Pinzón, G E Cely, and P A Serrano, “Chlorophyll concentration estimation using non-destructive methods in grapes (Vitis vinifera L.) cv. Riesling Becker”, Rev. Colomb. Cienc. Hortic, vol. 12, no. 2, pp. 329–337, May 2018.