A. Gutiérrez-Mora, J. P. Arana-Gutiérrez, E. Tapia-Campos, and B. Rodríguez-Garay, “Molecular analysis of sexual and asexual genetic variation of two sympatric Agave angustifolia varieties”, J PROF ASSOC CACTUS, vol. 12, pp. 155–165, Nov. 2010.