1. Sauer JD (1990) Amine oxides. In: Richmond JM (ed) Cationic surfactants: organic chemistry. Surfactant science series, vol 34. Marcel Dekker, Inc., USA, pp 275–295
2. Vaikunth SP (1999) Synthesis of tertiary amine oxides. US Patent 5,866,718
3. Sprung JA (1962) Polivinyl alcohol photographic silver halide emulsions. Ger Patent 1,139,738
4. Cook EW, Moss PH (1944) Quaternary ammonium compounds. US Patent 2,459,062
5. Dassanayake NL, Schlitzer RL, Park J (1997) Use of amidoamines in ophthalmic compositions. US Patent 5,631,005