Fahey, D., R. Gao, K.S. Carslaw, J. Kettleborough, P. Popp, M.J. Northway, J.C. Holecek, S. Ciciora, R. McLaughlin, T. Thompson, R.H. Winkler, D. Baumgardner, B. Gandrud, P. Wennberg, S. Dhaniyala, K. McKinney, Th. Peter, R. Salawitch, T.P. Bui, J.W. Elkins, C.R. Webster, E. Atlas, H. Jost, J. Wilson, R.L. Herman, and A.K.M. von Konig (2001), The detection of large HNO3-containing particles in the winter artic stratosphere, Science, 291, 1026-1031.