Hidden Variables

Ace, 1981 First printing July 1981 in Very Good Plus condition. A Paperback Original. Signed on the title page (signature only) by Charles Sheffield.. Signed by Author. Mass Market Paperback. Very Good Plus.

Ace, 1981. Later Edition. Mass Market (i.e. 4 by 7 inch softcover). N/A (volume is softcover). Used

Penguin Publishing Group, 1981. Mass Market Paperback. Good. Pages can have notes/highlighting. Spine may show signs of wear. ~ ThriftBooks: Read More, Spend Less.Dust jacket quality is not guaranteed.

Ace Books, 1981. Mass Market Paperback. Acceptable. Readable copy. Pages may have considerable notes/highlighting. ~ ThriftBooks: Read More, Spend Less.Dust jacket quality is not guaranteed.

Ace Books, 1981-07. Mass Market Paperback. Good.

Phoenix Pick. New. Special order direct from the distributor

Ace Books, 1981-07-01. Mass Market Paperback. New. New. In shrink wrap. Looks like an interesting title!

Paperback. New.