3Russell C E, Felker P. The Prickly-Pears (Opuntia sp., cactaceae): A source of Human and animal food in Semiarid Regions. [J]. Economic Botany, 1987,4(3) :433-445.
4Russell C E , Felker P. Comparative cold hardiness of Opuntia spp. and cvs. grown or fruit, vegetable and production. [J]. J. Hort. sci. ,1987,62:545 -550.
3Russell C E, Felker P. The Prickly-Pears (Opuntia sp., cactaceae): A source of Human and animal food in Semiarid Regions. [J]. Economic Botany, 1987,4(3) :433-445.
4Russell C E , Felker P. Comparative cold hardiness of Opuntia spp. and cvs. grown or fruit, vegetable and production. [J]. J. Hort. sci. ,1987,62:545 -550.
