L. S. Guerra and I. Álvarez Bello, “Effect of Pectimorf® - A traditional growth regulator on the development and distribution in clones ’CMC-40’ and ’Señorita’ of Cassava (Manihot esculenta Crantz) stomata”, J. Res. Bio, vol. 5, no. 6, pp. 1820-1828, Sep. 2015.