(EN) Swingle W.T., Reece P.C., The botany of Citrus and its wild relatives, in W. Reuther, H. J. Webber, and L. D. Batchelor [eds.], The citrus industry, vol. 1, History, world distribution, botany, and varieties, Berkeley, California, USA, University of California, 1967, pp. 190–430 (archiviato dall'url originale il 1º settembre 2013).
