Evan, W. C. 1976: Farmacognosia, p. 514-523. -Company editorial continental, Barcelona.
James, S. 1984: Lignotubers and burls. Their structure, function and ecological significence in Mediterranean ecosystems. -Bot. Rev. 50: 225-266.
Metcalfe C. R. & Chalk: L. 1950, Anatomy of dicotyledones vol 1: 512-533. -Oxford at the Claredon Press.
Solereder, H. 1908: Systmatic anatomy of the Dicotyledones vol. 1: 253-301. -Oxford at the Claredon Press.
Zargari, A 1990: Medicinal plants vol. 1: 660-663. -Tehran University Publication.
)
