Schinzer, Dieter; Bauer, Armin; Schieber, Jennifer Chemistry - A European Journal, 1999, vol. 5, # 9 p. 2492 - 2500 doi: 10.1002/(SICI)1521-3765(19990903)5:9<2492::AID-CHEM2492>3.0.CO;2-R