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3. National Institute of Standards and Technology (2014) Certificate of Analysis, Standard Reference Material® 1849a, Infant/Adult Nutritional Formula, Gaithersburg MD 20899, 29 April
4. National Institute of Standards and Technology (2014) Certificate of Analysis, Standard Reference Material® 1546a Meat Homogenate, Gaithersburg MD 20899, 2 May
5. National Institute of Standards and Technology (2014) Certificate of Analysis, Standard Reference Material® 1946 Lake Superior Fish Tissue, Gaithersburg MD 20899, 28 October