1. Hill-Cottingham, D. G. and Lloyd-Jones, C. P., Analysis of iron chelates in plant extracts. J. Sci. Food Agr.12, 69 (1961).
2. Hutner, S. H., Provasoli, L., Schatz, A., and Haskins, C. P., Some approaches to the study of the role of metals in the metabolism of micro-organisms. Proc. Am. Phil. Soc.94, 152 (1950).
3. Jacobson, L., Maintenance of iron supply in nutrient solutions by a single addition of ferric potassium ethylenediaminetetraacetate. Plant Physiol.26, 411 (1951).
4. Kroll, H., Knell, M., Power, J., and Simonian, J., A phenolic analog of ethylene-diaminetetraacetic acid. J. Am. Chem. Soc.79, 2024 (1957).
5. Morrison, G. H. and Freiser, H., Solvent Extraction in Analytical Chemistry, John Wiley and Sons, N.Y. 1st. Ed., p. 112 (1957).