Heat balance measurements - to quantify sap flow in thin stems only?
Herzog, K. M., Thum, R., Zweifel, R., & Häsler, R. (1997). Heat balance measurements - to quantify sap flow in thin stems only? Agricultural and Forest Meteorology, 83(1-2), 75-94. https://doi.org/10.1016/S0168-1923(96)02355-6