Coal conversion systems : technical data book / prepared for U.S. Department of Energy, Assistant Secretary for Energy Technology, Division of Coal Conversion. (OCLC #4131471)

We received as part of a gift an updating loose-leaf resource in three binders, and then discovered that we already had two copies on the shelf. But how to determine which is more up-to-date? Check the included metadata!

Each version included a full table of contents, with symbols indicating which sections were already included, and which were in preparation or planning phases. Rather than comparing that actual contents, I was able to compare these annotated tables of contents to determine that the copy we received as a gift had been more fully updated than the ones already in the collection.

Also, the gift copy was three full binders compared to the one-binder copies on the shelf, which was my other clue.