Original: Bottke W., Vokrouhlický D., Nesvorný D. (2007) An asteroid breakup 160 Myr ago as the probable source of the K/T impactor.
Simplified: Bottke WF, Vokrouhlický D Nesvorný D. (2007) An asteroid breakup 160 Myr ago as the probable source of the K/T impactor.