Dickson, Gordon R. Mankind on the Run.
Norton, Andre [Norton, Alice Mary]. The Crossroads of Time.
New York: published by Ace Books, 1956.
Small octavo, pictorial wrappers. Ace double #D-164. First printing and first paperback edition. Small tear to upper cover at spine edge to Crossroads, creasing and rubbing to covers and edges; creasing and rubbing to spine but not cracked; smudges to interior cover of Mankind on the Run; age tanned end pages, date stamp to bottom; age tanned text pages, some pages have top corners clipped (no text loss); Good.