Analysis "The behavior of inverted pendulum structures during earthquakes" Housner 1963 (pdf)
Experimental data "On the dynamics of rocking motion of single rigid-block structures" Peña et al. 2007 (pdf)
Listening to the coefficient of restitution Bernstein 1977
Further measurements of the bouncing of small latex spheres Dahneke 1975
Reflections on simultaneous impact (pdf) (movie) Smith, Kaufman, et al. 2012
Impulse-based simulation of rigid bodies Mirtich, Canny, 1995.
Impact (Dover Civil and Mechanical Engineering) Goldsmith 2001. I believe that this has a bunch of reference data for restitution experiments.