D. Reyes-López, J. Quiroz-Valentín, H. A. Kelso-Bucio, M. Huerta-Lara, C. H. Avendaño-Arrazate, and R. Lobato-Ortiz, “Stomatal characterization of five species of the genus Vanilla”., Agron. Mesoam., vol. 26, no. 2, pp. 237–246, Jun. 2015.