1. A. Biraghi, 1962 :Fomes annosusin Italy. In: IUFRO, Section 24; Conference and Study Tour onFomes annosus, Scotland, June 1960, p.16 .
2. T. E. Chase, 1986 : Genetics of sexuality and speciation in the fungal forest pathogenHeterobasidion annosum, Ph. D. Dissertation, University of Vermont, Burlington, 244 pp.
3. Heterobasidion Annosum, Root- and Butt-Rot of Trees