Madau, Piero Cosmology, MPI for Astrophysics, Max Planck Society;
Strigari, L. E., Bullock, J. S., Kaplinghat, M., Diemand, J., Kuhlen, M., & Madau, P. (2007). Redefining the missing satellites problem. Astrophysical Journal, 669(2 Part 1), 676-683. doi:10.1086/521914.