1. AOAC - Association of Official Analytical Chemists (1995) Official methods of analysis, 16th edn. Association of Official Analytical Chemists, Arlington
2. Ashraf M, Foolad MR (2007) Roles of glycine betaine and proline in improving plant abiotic stress resistance. Environ Exp Bot 59:206–216
3. Aslam M, Huffaker RC (1989) Role of nitrate and nitrite in the induction of nitrite reductase in leaves of barley seedlings. Plant Physiol 91:1152–1156
4. Barrie A, Prosser SJ (1996) Automated analysis of light-element stable isotopes by isotope ratio mass spectrometry. In: Boutton TW, Yamasaki S (eds) Mass spectrometry of soils. Marcel Dekker, New York, pp 1–46
5. Bendassolli JA, Trivelin PCO, Carneiro Júnior F (1997) Stable sulfur isotope fractionation by anion exchange chromatography. Production of compounds enriched in 34S. J Brazil Chem Soc 8:13–17