1. ASTM Standard D 2922–05 (2005) Standard test methods for density of soil and soil-aggregate in place by nuclear methods (shallow depth). Annual Book of ASTM Standards, ASTM International, West Conshohocken, PA
2. ASTM Standard D 5778–95 (1995) Standard test method for performing electronic friction cone and piezocone penetration testing of soils. Annual Book of ASTM Standards, ASTM International, West Conshohocken, PA
3. Dasari GR, Karthikeyan M, Tan TS, Mimura M, Phoon KK (2006) In situ evaluation of radioisotope cone penetrometers in clays. Geotech Test J 29:45–53
4. Ittisukananth P, Koga K, Vongthanasunthorn N, Liengcharernsit W, Ishii T (2007) Study on water quality and Chattonella in the Ariake Sea using water quality model. Reports of the Faculty of Science and Engineering, Saga University 36:53–58
5. ISSMFE (1989) International reference test procedure for cone penetration test (CPT). Report of the ISSMFE Technical Committee on Penetration Testing of Soils-TC 16, with Reference to Test Procedures. Swedish Geotechnical Institute, Linkoping, Information 7:6–16