1. Abubakr SM, Hrutfiord BF, Reichert TW, McKean WT 1997 Retention mechanism of metal ions in recycled and never-dried pulps. Tappi J 80: 143–148
2. Anonymous 1994 SIMAA 6000. Atomic absorption spectrometer. Perkin-Elmer Corporation, Überlingen, 32 pp
3. Anonymous 1995 Milestone application notes for microwave digestion. Milestone Application Lab, Bergamo, Sorisole, 256 pp
4. Anonymous 1997 A guide to techniques and applications of atomic spectroscopy. Norwalk, Connecticut, 41 pp
5. Bock R 1979 A handbook of decomposition methods in analytical chemistry. International Textbook Company, Edinburgh, 444 pp