"World War II Nazi Germany" . . . "Ruhrstahl X-7" . . "X-4 missile" . . "X-4" . . . . . . . . . "Ruhrstahl X-4" . "Kramer Rk 344" . . . . . . "Ruhrstahl Kramer X-7" . . "Ruhrstahl Kramer X-4" . "Ruhrstahl X-4" . . "X4" . . . . "Ruhrstahl X-4#X-7 anti-tank missile" . .