Boggs, Kate Doggett (1932). Prints and Plants of Old Gardens. Richmond, Virginia: Garrett & Massie, Publishers. pp. 21, 22, 81. Retrieved 11 January 2024.
Rohde, Eleanour Sinclair (1922). Old English Herbals. London: Longmans, Green and Co. pp. 163–166. Retrieved 11 January 2024.
Culpeper, Nicholas (1662). The English Physitian Enlarged. London: A. and J. Churchill. pp. 3–4. Retrieved 11 January 2024.