Bagnulo, S., Tozzi, G. P., Boehnhardt, H., Vincent, J.-B., & Muinonen, K. (2010). Polarimetry and photometry of the peculiar main-belt object 7968 = 133P/Elst-Pizarro. Astronomy and Astrophysics, 514: A99. doi:10.1051/0004-6361/200913339.