Forestry Commission field book
HMSO
by Ian Willoughby and David Clay
HMSO c1996 Forestry Commission field book 14
J.L. Innes
HMSO c1990 Forestry Commission field book 12
Available at 2 libraries
by T.J.D. Rollinson
HMSO 1988 Forestry Commission field book 2
Available at 1 libraries