1. Co-ordinated research programme on human dietary intakes of nutritionally important trace elements as measured by nuclear and other techniques, international atomic energy agency (1985) Vienna, Austria. Report of the first research coordination meeting Gaithersburg, Beltsville and Washington, DC, p 19?22
2. Donnelly J, McClellan K, Walker J, Robinson D (1989) Food Chem 33:243?270
3. Giannopolitis C, Ries S (1977) Plant Physiol 59:315?318
4. Hicks C (1980) J Dairy Sci 63:529?532
5. Sutton J, Goodwin J, Horscroft G, Stockdale R, Frake A (1983) Assoc Off Anal Chem 66:1164?1174