Donato, Virgínia Maria Tenorio Sabino, et al. “Metabolism of Sugar Cane Plant Cultivated in Vitro at Different Nitrogen Levels”. Pesquisa Agropecuaria Brasileira, vol. 38, no. 12, Dec. 2003, pp. 1373-9, doi:10.1590/S1678-3921.pab2003.v38.6714.