Rulon, L. L., Robertson, J. D., Lovell, M. A., Deibel, M. A., Ehmann, W. D., & Markesber, W. R. (1969). Serum zinc levels and Alzheimer's disease. Biological Trace Element Research, 75(1-3), 79-85. https://doi.org/10.1385/bter:75:1-3:79 (Original work published 1969)