Kofman, W., Herique, A., Barbin, Y., Barriot, J.-P., Ciarletti, V., Clifford, S., et al. (2015). Properties of the 67P/Churyumov-Gerasimenko interior revealed by CONSERT radar. Science, 349(6247): aab0639. doi:10.1126/science.aab0639.