Durley, R C and Kannangara, T and Simpson, G M and Seetharama, N  (1983) Drought resistance of Sorghum bicolor. 5. Genotypic differences in the concentrations of free and conjugated abscisic, phaseic and indole-3-acetic acids in leaves of field-grown drought-stressed plants.  Canadian Journal of Plant Science, 63 (1).  pp. 131-145.  ISSN 1918-1833