Books#1-4 and#6 in the series. Ace Books paperback editions (1987-1988). Various authors. Books#2-4 and#6 are first printings with full number line on copyright page. Book#1 is likely a first printing as well but there is no number line on copyright page. The 5 paperbacks are in Good condition. Wear on edges. Tanned pages. Crease on top corner of#6.