Marais, J., C.J. van Wyk, and A. Rapp. 2017. “Effect of Sunlight and Shade on N Orisoprenoid Levels in Maturing Weisser Riesling and Chenin Blanc Grapes and Weisser Riesling Wines”. South African Journal of Enology and Viticulture 13 (1):23-32. https://doi.org/10.21548/13-1-2191.