Hodgson, Willard (1967–1989) [1943]. "Chapter 4: Horticultural Varieties of Citrus". Dalam Webber, Herbert John; rev Walter Reuther and Harry W. Lawton (penyunting). The Citrus Industry. Riverside, California: University of California Division of Agricultural Sciences. Diarkibkan daripada yang asal pada 2012-02-05.
lib.ucr.edu
Webber, Herbert John; Reuther, Walter; Lawton, Harry W. (1967–1989) [1903]. "The Citrus Industry". Riverside, California: University of California Division of Agricultural Sciences. Diarkibkan daripada yang asal pada 2004-06-04.
web.archive.org
Hodgson, Willard (1967–1989) [1943]. "Chapter 4: Horticultural Varieties of Citrus". Dalam Webber, Herbert John; rev Walter Reuther and Harry W. Lawton (penyunting). The Citrus Industry. Riverside, California: University of California Division of Agricultural Sciences. Diarkibkan daripada yang asal pada 2012-02-05.
Webber, Herbert John; Reuther, Walter; Lawton, Harry W. (1967–1989) [1903]. "The Citrus Industry". Riverside, California: University of California Division of Agricultural Sciences. Diarkibkan daripada yang asal pada 2004-06-04.