https://docs.google.com/viewer?a=v&q=cache:-LeNiihg1m0J:www.rand.org/pubs/monograph_reports/MR1209/MR1209.appc.pdf+asteroids+earth+impact+weapon&hl=es&gl=ar&pid=bl&srcid=ADGEESgizHwWZjkNLIUWo4NKR3YEzU4gQf7kDmxSPOvZYlFz5p_88hYxpadlEVay0ZsUo3WSxlcf_SezDBlrMT9b_ZeE0tbygNMVRkgjexl3c6I0BFXoXbqr9TNFssL5N_zuUFS-vE5a&sig=AHIEtbRaAC6TEH74ecEFSBX33DT4ksvNoQ
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