1. 1) F.P. Tredwell and W.S. Hall: Analytical Chemistry, 7th Ed., Vol. 1, p.250 (1937)
2. 2) K. Kimura ea al.: Radiochemical Analysis of“Bikini Ashes”fallen on Board the No. 5 Fukuryu Maru on March 1, 1954. Japan Analyst 3 (4) , 335-348 (1954) (in Japanese with English summary)
3. 3) M. Yatazawa: Radiological Contamination of Agricultural Products, Ten-mon To Kisho, No. 10, 40 (1954) (in Japanese)
4. 4) Y. Sugiura : Artificial Radioactivity in Sea Water, Sokko Jiho, 22 (3) 66-74 (1955) (in Japanese)
5. 5) S. Okano : unpublished data