Singh, H.,
D. Herlth, D. O’Hara, J. Bradshaw, S. Sandholm,
R. Talbot, P. Crutzen, and M. Kanakidou (1992), Relationship of PAN to Active and Total Odd Nitrogen at Northern High Latitudes: Influence of Reservoir Species on NOx and O3,
J. Geophys. Res., 97, 16,523-16.