1. Bonner, J., Heftmann, E., Zeevaart, J. A. D., Plant Physiol., 38, 81 (1963).
2. Sironval, C., C.R. de Recherches Tray. Gen. Rech. des Hormones Vegetales (1952–1956), I.R.S.I.A., Bruxelles, Belgium, cited by Hillman, W. S., The Physiology of Flowering (Holt, Rinehart and Winston, New York, 1963).
3. Chan, A. P., Proc. Amer. Soc. Hort. Sci., 55, 461 (1950).
4. Johansen, D. A., Plant Microtechnique (McGraw-Hill Company, Inc., New York, 1940).
5. Pratt, C., and Wetmore, R. H., Stain Technique, 26, 251 (1951).