Soviet Militairy Space Doctrine Space weapons : a handbook of military astronautics / ed. by James H. Straubel ... [et al.] Behind the flying saucers / F. Scully case for the UFO : unidentified flying objects / M.K. Jessup Inside the space ships / by George Adamski ; foreword by Desmond Leslie Vliegende schotels slaan ons gade / door Donald E. Keyhoe ; [vert. uit het Engels door André E. Steentjes] Flying saucers / Donald H. Menzel defense space interests Hearings before the committee on science and astronautic U.S. House of Representatives 87th congress, 1st Session, 17 - 23 march 1961 Vliegende schotels in actie / Harold T. Wilkins ; geautoriseerde vertaling [uit het Engels] André E. Steentjes report on unidentified flying objects / E.J. Ruppelt Sternenkriege" : Illusionen und Gefahren
