Liên quan Interplanetary Transport System Interplanetary Phenomenon Unit Interplanetary magnetic field
Tài liệu tham khảo WikiPedia: Interplanetary Phenomenon Unit http://www.majesticdocuments.com/official/foia.php http://www.totse.com/en/fringe/flying_saucers_from... http://www.cufon.org/cufon/foiasop.htm https://web.archive.org/web/20070926235819/http://...
