Snodgrass, C., Jehin, E., Manfroid, J., Opitom, C., Fitzsimmons, A., Tozzi, G. P., et al. (2016). Distant activity of 67P/Churyumov-Gerasimenko in 2014: Ground-based results during the Rosetta pre-landing phase. Astronomy and Astrophysics, 588: A80. doi:10.1051/0004-6361/201527834.