BEIN Tanselle H13 2531: Original green wrappers; large union device on back cover. "Big blue book" series title missing. Publisher's advertisements on 2 pages at end, not noted in pagination.
BEIN Tanselle H13 2532: Original green wrappers; large union device on back cover. "Big blue book" series title missing. Publisher's advertisements on 2 pages at end, not noted in pagination.