E. H. de Souza, N. R. Paim, M. T. Schifino, and J. Riboldi, “Morphological and physiological characterization of diploid and tretraploid forms of Trifolium riograndense in comparison with Trifolium repens and Trifolium polymorphum”, PAB, vol. 23, no. 6, pp. 599–607, Apr. 2014, doi: 10.1590/S1678-3921.pab1988.v23.13931.