Sommer, K. ., F. Hancock, and M. Downey. “Resilience of Sultana (Vitis Vinifera) to Drought and Subsequent Recovery: Field Evaluation of Nine Rootstock Scion Combinations”. South African Journal of Enology and Viticulture, vol. 31, no. 2, Dec. 2016, pp. 181-5, doi:10.21548/31-2-1416.