A comparison of isozyme and morphological markers to assess the within population variation in small populations of European aspen (Populus tremula L.) in Spain

1. Lopez-De-Heredia, U.
2. Sierra-De-Grado, R.
3. Cristóbal, M.D.
4. Martínez-Zurimendi, P.
5. Pando, V.
6. Martín, M.T.