1. Aubinet, M., A. Grelle, A. Ibrom, Ü. Rannik, J. Moncrieff, T. Foken, A. S. Kowalski, P.H. Martin, P. Berbigier, C. Bernhofer, R. Clement, J. Elbers, A. Granier, T. Grünwald, K. Morgenstern, K. Pilegaard, C. Rebmann, W. Snijders, R. Valentini, and T. Vesala, Estimates of the annual net carbon and water exchanges of forests: The EUROFLUX methodology, Advances in Ecological Research, 30, 114–175, 2000.
2. Baldocchi, D. D., E. Falge, L. Gu, R. Olson, D. Hollinger, S. Running, P. Anthoni, C. Bernhofer, K. Davis, J. Fuentes, A. Goldstein, G. Katul, B. Law, X. Lee, Y. Malhi, T. P. Meyers, J. W. Munger, W. Oechel, K. Pilegaard, H. P. Schmid, R. Valentini, S. Verma, T. Vesala, K. Wilson, and S. Wofsy, FLUXNET: A new tool to study the temporal and spatial variability of ecosystem-scale carbon dioxide, water vapor and energy flux densities, Bull. Amer. Meteorol. Soc., 82, 2415–2435, 2001.
3. Baldocchi, D. D., B. B. Hicks, and T. P. Meyers, Measuring biosphere-atmosphere exchanges of biologically related gases with micrometeorological methods, Ecology, 69, 1331–1340, 1988.
4. Bradley, N. L., A. C. Leopold, J. Ross, and W. Huffaker, Phenological changes reflect climate change in Wisconsin, Proc. Natl. Acad. Sci. (USA), 96, 9701–9704, 1999.
5. Chmielewski, F.-M, The International Phenological Gardens across Europe: Present state and perspective, Phenol. Seasonality, 1, 19–23, 1996.