Morphological variability of oaks (Quercus robur L, Quercus petraea (Matt) Liebl, Quercus pubescens Willd) in northeastern France: preliminary results JL Dupouey and V BadeauAnn. For. Sci., 50 Supplement (1993) 35s-40sDOI: https://doi.org/10.1051/forest:19930702