Hour Of The Horde by Gordon R. Dickson: The voracious and merciless Horde roved the galaxies, stripping whole star systems of all life. As they advance on the Milky Way, a galaxy-wide force is hastily arrayed to stop them. But Miles Vander, the warrior sent by Earth to join the defence, must first convince his alien crewmembers that he is just as good a soldier as they. Wolfing by Gordon R. Dickson: Earth was only a primitive outpost, its people dubbed primitive "wolfings" by the rulers of the galactis empire. Jim Kell was sent to the High-Born rulers' Throne World, with orders only to observe - until he cast away his orders from Earth and proved himself a Wolfling indeed. Gremlins Go Home by Gordon R. Dickson and Ben Bova: Suppose that elves, gremlins, and leprechauns are really tiny aliens marooned on Earth for hundreds of years. They want to go home, and human technology finally can make it possible - it they can get aboard NASA's Mars rocket and hijack it! Pity the poor human who has to help them with the big heist...