Taxus baccata

*Harte, J. (1996). How old is that old yew? At the Edge 4: 1-9. Available online.
*Kinmonth, F. (2006). Ageing the yew - no core, no curve? International Dendrology Society Yearbook 2005: 41-46.
*Lewington, A., & Parker, E. (1999). Ancient Trees: Trees that Live for a Thousand Years. London: Collins & Brown Ltd. ISBN 1855857049
*(e-Keltoi) Francisco Marco Simón, The Celts in the Iberian Peninsula 6: 287-345, 2005.
*Druid Network: Yew
*Fortingall Yew