Bishop, K.A., Lemonnier, P., Quebedeaux, J.C., Montes, C.M., Leakey, A.D.B. and Ainsworth, E.A. 2018. Similar photosynthetic response to elevated carbon dioxide concentration in species with different phloem loading strategies. Photosynthesis Research 137: 453-464.

Burkart, S., Manderscheid, R. and Weigel, H.-J. 2009. Canopy CO2 exchange of sugar beet under different CO2 concentrations and nitrogen supply: results from a free-air CO2 enrichment study. Plant Biology 11 (Suppl. 1): 109-123.

Ignatova, L.K., Novichkova, N.S., Mudrik, V.A., Lyubimov, V.Yu., Ivanov, B.N. and Romanova, A.K. 2005. Growth, photosynthesis, and metabolism of sugar beet at an early stage of exposure to elevated CO2. Russian Journal of Plant Physiology 52: 158-164.

Romanova, A.K., Mudrik, V.A., Novichkova, N.S., Demidova, R.N. and Polyakova, V.A. 2002. Physiological and biochemical characteristics of sugar beet plants grown at an increased carbon dioxide concentration at various nitrate doses. Russian Journal of Plant Physiology 49: 204-210.

Taylor, S. E. and Terry, N. 1984. Limiting factors in photosynthesis. V. Photochemical energy supply co-limits photosynthesis at low values of intercellular CO2 concentration. Plant Physiology 75: 82-86.