00451nam a2200133Ia 4500008004100000082002200041100001800063245003800081260006600119300000900185490005900194600001700253650004700270140224s9999    xx            000 0 und d  a631.52+575:634 H5  aRichens, R.H.  aForest tree breeding and genetics  aEnglandbImperial Bureau of Plant Breeding and Geneticsc1945  a79p.  aImperial Agricultural Bureaux, Joint Publication; no.8  aR.H. Richens  aArboriculture,Tree breeding,Plant genetics