1. The Power of Movement in Plants;Darwin,1881
2. Observations on stomata;Darwin;Philos. Trans. R. Soc. London Ser. B,1898
3. On a new method of estimating the aperture of stomata;Darwin;Proc. R. Soc. London B Biol. Sci.,1911
4. Die Gestalts- und Lageveränderung der Pflanzen-Chromatophoren;Senn,1908
5. Lectures on the Physiology of Plants;Sachs,1887