NASA - National Aeronautics and Space Administration

Murphy, D., D. Fahey, M. Proffitt, S. C. Liu, R. Chan, C. S. Eubank, S. R. Kawa, and K. Kelly (1993), Reactive nitrogen and its correlation with ozone in the lower stratosphere and upper tropospere, J. Geophys, Res., 98, 8751-8773.