Gods, Myths & Heroes of Legend

Celtic Goddesses: Warriors, Virgins, and Mothers, Miranda Green
Celtic Gods Celtic Goddesses, Miranda Gray, Courtney Davis, R. J. Stewart
Celtic Mythology, John A. MacCulloch
Celtic Mythology, Simon Goodenough
Celtic Mythology: The Myths and Legends of the Celtic World, Arthur Cotterell
Celtic Myths (The Legendary Past), Miranda Jane Green
Celtic Myths & Legends, O. B. Duane
Celtic Myth & Legend: An A-Z of People and Places, Mike Dixon-Kennedy
The Creatures of Celtic Myth, Bob Curran, Andrew Whitson (Illustrator)
Dictionary of Celtic Myth and Legend, Miranda J. Green
Dictionary of Celtic Mythology, Peter Berresford Ellis 
Dictionary of Celtic Mythology, James MacKillop
An Encyclopedia of Celtic Mythology, Bob Curran