1. Hardy, E. P., P. W. Krey and H. L. Volchok, 1972: Global inventory and distribution of Pu-238 from SNAP-9A, HASL 250, 1-32.
2. Plutonium content of river water in Japan.
3. Katsuragi, Y., 1976: Radioactive fallout in Japan, Tenki, 23, 334-345, (in Japanese).
4. Krey, P. W., E. P. Hardy, C. Pachicki, F. Rourke, J. Coluzza and W. K. Benson, 1976: Mass isotopic composition of global fallout plutonium in soil, in Transuranium Nuclides in the Environment, pp. 671-676, IAEA, Vienna.
5. Miyake, Y., Y. Katsuragi and Y. Sugimura, 1968: Deposition of plutonium in Tokyo through the end of 1966, Pap. Met. Geophys., 19, 267-276.