Martin, Harry J.; Drescher, Martina; Khlig, Hanspeter; Schneider, Sabine; Mulzer, Johann Angewandte Chemie - International Edition, 2001, vol. 40, # 17 p. 3186 - 3188 doi: 10.1002/1521-3773(20010903)40:17<3186::AID-ANIE3186>3.0.CO;2-W