TY - GEN AU - Johnson, P. S., CN - HD45 ID - 26496 KW - Ground-effect machines. KW - Technological innovations. KW - Innovations. KW - Economic issues SN - 0855200782 T1 - The economics of invention and innovation :with a case study of the development of the hovercraft / TI - The economics of invention and innovation :with a case study of the development of the hovercraft / ER -