''We are 15 million years overdue for an asteroid strike''

''The main goal of this study was to find feasible methods and strategies for the deflection of large asteroids in the diameter range of 5 to 200 km.''

To the deflection of asteroids in the diameter range of 5 to 200 km (H.K. Hahn, 2014)

https://archive.org/details/ToTheDeflectionOfAsteroidsInTheDiameterRangeOf5To200Km