1. 3) a) Graf, F., Kroeger, K., Reimert, R. : Sulfur-free odorization with gasodor S-free — A review of the accompanying research and development activities, Energy & Fuels, 21 (6), 3322-3333 (2007). b) Imamura, D., Oyakawa, K., Hashimasa, Y., Akai, M., Watanabe, S. : Adaptability of sulfur-free odorous compounds to hydrogen odorant for fuel cell vehicles, Review of Automotive Engineering, 27 (3), 417-423 (2007).
2. 4) a) Hennings, U., Reimert, R. : Behaviour of sulfur-free odorants in natural gas fed PEM fuel cell systems, Fuel Cells, 7 (1), 63-69 (2007). b) Braun, N., Eilers, J., Mueller, D. (Symrise Gmbh & Co.KG) : Odornt for hydrogen based on acrylate, PCT Int.Appl., WO2006067112 (2006), PCT Int. Appl., WO2006067113 (2006), PCT Int.Appl., WO2006067111 (2006), PCT Int. Appl., WO2006067115 (2006). c) Schmeer, F. : Sulfur-free odorizing agent, Energie Wasser Praxis, 53 (11), 38-40 (2002). d) Kato, Yutaka (Soda Aromatic Co., Ltd) : PCT Int. Appl (2003), WO2003044135. e) Nemoto, T., Kondo, T., Namba, M. (Koatu gas Hoan Kyoukai, Riken Perfumery Co., Ltd.) : Gas odorant for fuel gas with reduced environment pollution, Jpn.Kokai Tokkyo koho, 2002356688 (2002).
3. 7) a) D.V. Sweet : (1993), “Registry of Toxic Effects of Chemical Substances, Rtecs : A Comprehensive Guide”, Diane Pub Co. b) http://www.symyx.com/products/databases/bioactivity/rtecs/index.jsp