Bettoni, M.M., Mogor, A.F., Pauletti, V. and Goicoechea, N. 2017. The interaction between mycorrhizal inoculation, humic acids supply and elevated atmospheric CO2 increases energetic and antioxidant properties and sweetness of yellow onion. Horticulture, Environment, and Biotechnology 58: 432-440.

Jasoni, R., Kane, C., Green, C., Peffley, E., Tissue, D., Thompson, L., Payton, P. and Pare, P.W. 2004. Altered leaf and root emissions from onion (Allium cepa L.) grown under elevated CO2 conditions. Environmental and Experimental Botany 51: 273-280.