Talbot, R., J.D. Bradshaw, S.T. Sandholm, H.B. Singh, G. Sachse, J. Collins, G.L. Gregory, B.E. Anderson, J. Barrick, E. Browell, K. Klemm, B. Lefer, O. Klem, K. Gorzelska, J. Olson, D. Herlth, and D. O'Hara (1993), Summertime distributions and relations of reactive odd-nitrogen species and NOy in the troposphere over Canada, J. Geophys. Res..