Baeurle, Stefan; Hoppen, Sabine; Koert, Ulrich Angewandte Chemie - International Edition, 1999, vol. 38, # 9 p. 1263 - 1266 doi: 10.1002/(SICI)1521-3773(19990503)38:9<1263::AID-ANIE1263>3.0.CO;2-2