1. Grob K, Lanfranchi M, Artho A (1991) J AOAC (in press)
2. Grob K, Biedermann M, Caramaschi A, Pacciarelli B (1991) HRC 14:33?39
3. Grob K, Biedermann M, Artho A, Egli J (1991) J Food Additives Contam (in press)
4. Micali G, Lanuzza F, Curro P, Calabro G (1990) J Chromatogr 514:317?324
5. Büchi J, (1976) Pharmacopoea Helvetica, 6th ed. Eidgenössische Druck und Materialzentrale, Bern, p 1107