U.S. Department of Agriculture, Human Nutrition Information Service, Exler, J. and Weirauch, J.L.
HNIS/PT 103: Provisional Table on the Content of Omega-3 fatty Acid and other Fat Component in Selected Foods.
U.S. Department of Agriculture, Nutrient Data Research Branch
If the same reference is mentioned several times, it indicates that the
value is composed of several values from the same reference.