Henry's books can be bought from most online bookstores, and can be ordered from your local bookstore if you give them the ISBN. Alternatively you can order them directly from Leabhar Cnoc Mhuilinn's US printer. Follow these links to order your book:-

Purchase Europa's Crossing
direct from Leabhar Cnoc Mhuilinn

Purchase Venus and the Sea People
direct from Leabhar Cnoc Mhuilinn

Purchase Hermes and the Sea People
direct from Leabhar Cnoc Mhuilinn

Purchase Jove and the Sea People
direct from Leabhar Cnoc Mhuilinn

Purchase Saturn and the Sea People
direct from Leabhar Cnoc Mhuilinn