1. Swingle, W. T. & Reece, P. C. In The Citrus Industry, History, World Distribution, Botany, and Varieties, Vol. 1 (eds Reuther, W. et al.) 190–143 (Univ. of California Press, 1967).
2. Morton, C. M. & Telmer, C. New subfamily classification for the Rutaceae. Ann. Mo. Bot. Gard. 99, 620–641 (2014).
3. Bayer, R. J. et al. A molecular phylogeny of the orange subfamily (Rutaceae: Aurantioideae) using nine cpDNA sequences. Am. J. Bot. 96, 668–685 (2009).
4. Tanaka, T. Fundamental discussion of Citrus classification. Stud. Citrologia 14, 1–6 (1977).
5. Tolkowsky, S. Hesperides: a History of the Culture and Use of Citrus Fruits (J. Bale, Sons & Curnow, 1938).