1 American Rocket Society Reports,1958,march 17-20,No589,590.2 Plastics World,1958,Apr,Vol,16,No4,p.4~6.3 Western Plastics,1957,15Dec,,Vol.4,No12,p.15.4 Western Plastics,1957,15 June,Vol.4,No6,p.12.5 Western Plastics,1957,May,Vol,4,No5,p,23-25.6 Air Force,1958,Jan.,vol.41,No1,p.82.7 Chaudronnerie-Tolerie,1958,Mai,p.13.