Do Androids Dream of Electric Sheep Omnibus

San Francisco lies under a cloud of radioactive dust. The World War has killed millions, driving entire species to extinction and sending mankind off-planet. Those who remain covet any living creature, and for people who can't afford one, companies build incredibly realistic fakes: horses, birds, cats, sheep...even humans. Rick Deckard is an officially sanctioned bounty hunter tasked to find six rogue androids. They're machines, but look, sound, and think like humans