Observations of large reductions in the NO/NOy ratio near the mid-latitude...
Keim, E. R., D. Fahey, L. A. Del Negro, E. L. Woodbridge, R. Gao, P. Wennberg, R. C. Cohen, R. Stimpfle, K. Kelly, E. Hintsa, J. Wilson, H. Jonsson, Dye, D. Baumgardner, S. R. Kawa, R. Salawitch, M. Proffitt, M. Loewenstein, J. Podolske, and R. Chan (1996), Observations of large reductions in the NO/NOy ratio near the mid-latitude tropopause and the role of heterogeneous chemistry, Geophys. Res. Lett., 23, 3223-3226.