Grygorieva, O., V. Abrahamová, M. Karnatovská, R. Bleha, and J. Brindza. “Morphological Characteristic of Fruit, Drupes and Seeds Genotypes of Ziziphus Jujuba Mill.”. Potravinarstvo Slovak Journal of Food Sciences, Vol. 8, no. 1, Dec. 2014, pp. 306-14, doi:10.5219/414.