References
- 1975 . Official Methods of Analysis , 12th Ed. , 177 Washington, D. C. : AOAC . secs 6.176–6
- Guerin , M. R. , Olerick , G. and Horton , A. D. 1974 . J. Chromatogr. Sci. , 12 : 385
- Feyerabend , C. , Levitt and Russell , M. A.H. 1975 . J. Pharm. Pharmac. , 27 : 434
- Watson , I. D. 1977 . J. Chromatogr. , 143 : 203