1. Impacts on the earth by asteroids, comets;Chapman;Nature,1994
2. The impact hazard;Morrison,1994
3. Influx of interplanetary bodies onto earth;Ceplecha;Astronomy and Astrophysics,1992
4. Impacts of meteorioids larger than 1m onto the earth's atmosphere;Ceplecha;Astronomy and Astrophysics,1994
5. The 1908 Tunguska explosion;Chyba;Nature,1993