Catão, Hugo Cesar Rodrigues Moreira, et al. “Physiological and Biochemical Aspects of Lettuce Seed Germination at Different Temperatures”. Pesquisa Agropecuaria Brasileira, vol. 49, no. 4, June 2014, pp. 316-22, doi:10.1590/S1678-3921.pab2014.v49.18743.