The discovery of the element, now discredited, was made by Enrico Fermi and a team of scientists at the University of Rome in 1934. In the same year Ida Noddack had already presented alternative explanations for the experimental results of Fermi. Following the discovery of nuclear fission in 1938, it was realized that Fermi's discovery was actually a mixture of barium, krypton, and other elements. The actual element was discovered several years later, and assigned the name neptunium.
- Fermi, E. (1934). "Possible Production of Elements of Atomic Number Higher than 92". Nature. 133 (3372): 898–899. Bibcode:1934Natur.133..898F. doi:10.1038/133898a0.
- Sime, Ruth Lewin (2000). "The Search for Transuranium Elements and the Discovery of Nuclear Fission". Physics in Perspective. 2 (1): 48–62. Bibcode:2000PhP.....2...48S. doi:10.1007/s000160050036.
- Noddack, Ida (1934). "Über das Element 93". Angewandte Chemie. 47 (37): 653. doi:10.1002/ange.19340473707.
- Element name etymologies. Retrieved February 23, 2010.
- Enrico Fermi, Artificial radioactivity produced by neutron bombardment, Nobel Lecture, December 12, 1938.