Planck Collaboration, Ade, P. A. R., Aghanim, N., Arnaud, M., Ashdown, M., Aubourg, E., et al. (2016). Planck intermediate results - XXXVII. Evidence of unbound gas from the kinetic Sunyaev-Zeldovich effect. Astronomy & Astrophysics, 586: A140, pp. 1-14. doi:10.1051/0004-6361/201526328.