Schmid, B., R.A. Ferrare, C. Flynn, R. Elleman, D. Covert, A. Strawa, E. Welton, D. Turner, H.H. Jonsson, J. Redemann, J. Eilers, K. Ricci, G. Hallar, M. Clayton, J. Michalsky, A. Smirnov, B.N. Holben, and J. Barnard (2006), How well do state-of-the-art techniques measuring the vertical profile of tropospheric aerosol extinction compare?, J. Geophys. Res., 111.