Wartinger, A., Heilmeier, H., Hartung, W., & Schulze, E. D. (1990). Daily and seasonal
course of leaf conductance and abscisic acid in the xylem sap of almond trees (Prunus dulcis (Miller) D.A. Webb) under desert
conditions. New Phytologist, 116(4), 581-587. doi:10.1111/j.1469-8137.1990.tb00542.x.