1. ISO 2871-1: 1988: Surface active agents—Detergents—Determination of cation-active matter content—Part 1: High-molecular-mass cation-active matter. International Organization for Standardization, Geneva.
2. ISO 2871-2: 1990: Surface active agents—Detergents—Determination of cation-active matter content—Part 2: Cation-active matter of low molecular mass (between 200 and 500). International Organization for Standardization, Geneva.
3. Cullum, D. C. Proc. IIIrd International Congress on Surface Active Substances, Cologne, 1960, Vol. C, pp. 42–50.
4. Cross, J. T. Analyst, 90 (1965), 315–324.
5. Patel, D. M. and Anderson, R. A. Drug Standards, 26 (1958) 189.