@article{small,
  title={Experimental evidence for the impact ejection of viable microorganisms from Mars and Mars-like planets},
  author={Stöffler, D., Horneck, G., Ott, S., Hornemann U., Cockell, C.S., Moeller, R., Meyer, C., de Vera, J.P., Fritz, F., and Artemieva, N.A.},
  journal={Icarus},
  volume={186},
  pages={585-588},
  year={2007}
}