Hofmann, D. J., & Rosen, J. M. (1984). Balloonborne particle counter observations of the El Chichón aerosol layers in the 0.01 - 1.8 µm radius range. Geofísica Internacional, 23(2), 155–185. https://doi.org/10.22201/igeof.00167169p.1984.23.2.836