Harmonisation of Regulatory Oversight in Biotechnology ...
OECD
Hawley, G.J., D.H. DeHayes and G.J. Badger. 2000. Red and black spruce
introgression in montane ecosystems in New England and New York. J. Sustain.
For. 10: 327-333. Heinselman, M.L. 1957. Silvical characteristics of black spruce.