Snodgrass, C., Barrera, L., Boehnhardt, H., Guilbert-Lepoutre, A., Hainaut, O., Hutsemékers, D., Jehin, E., Meech, K., Opitom, C., Schulz, R., Tozzi, G. P., & Tubiana, C. (2014). The activity cycle of 67P/Churyumov-Gerasimenko.