Aranda, X., Agusti, C., Joffre, R. and Fleck, I. 2006. Photosynthesis, growth and structural characteristics of holm oak resprouts originated from plants grown under elevated CO2. Physiologia Plantarum 128: 302-312.

Arena, C., Vitale, L. and Virzo de Santo, A. 2005. Photosynthetic response of Quercus ilex L. plants grown on compost and exposed to increasing photon flux densities and elevated CO2. Photosynthetica 43: 615-619.

Blaschke, L., Schulte, M., Raschi, A., Slee, N., Rennenberg, H. and Polle, A. 2001. Photosynthesis, soluble and structural carbon compounds in two Mediterranean oak species (Quercus pubescens and Q. ilex) after lifetime growth at naturally elevated CO2 concentrations. Plant Biology 3: 288-297.

Grulke, N.E. and Paoletti, E. 2005. A field system to deliver desired O3 concentrations in leaf-level gas exchange measurements: Results for Holm oak near a CO2 spring. Phyton 45: 21-31.

Marek, M.V., Sprtova, M., De Angelis, P. and Scarascia-Mugnozza, G. 2001. Spatial distribution of photosynthetic response to long-term influence of elevated CO2 in a Mediterranean macchia mini-ecosystem. Plant Science 160: 1125-1136.

Paoletti, E., Seufert, G., Della Rocca, G. and Thomsen, H. 2007. Photosynthetic responses to elevated CO2 and O3 in Quercus ilex leaves at a natural CO2 spring. Environmental Pollution 147: 516-524.

Rapparini, F., Baraldi, R., Miglietta, F. and Loreto, F. 2004. Isoprenoid emission in trees of Quercus pubescens and Quercus ilex with lifetime exposure to naturally high CO2 environment. Plant, Cell and Environment 27: 381-391.

Tognetti, R., Johnson, J.D., Michelozzi, M. and Raschi, A. 1998. Response of foliar metabolism in mature trees of Quercus pubescens and Quercus ilex to long-term elevated CO2. Environmental and Experimental Botany 39: 233-245.