J. G. Martínez-Ávalos, J. Golubov, M. C. Mandujano, and E. Jurado, “Causes of individual mortality of ‘false peyote’ Astrophytum asterias (cactaceae); a threatened Cactaceae: the effect of damage by grazing in Mexican populations”, CienciaUAT, vol. 3, no. 1, pp. 70-74, Sep. 2008.