Gibraltar Errors and Varieties 1886-2000, by R G W Burton.

Published by The Gibraltar Study Circle, 2000.  Sp/B, 71pp.

Arranged by SG number, this catalogue lists major errors, double printings, watermark varieties, constant varieties, non constant varieties, retouches and re-entries, misplaced and double perforations, perforation shifts, colour shifts and doctor blade flaws.  Illustrated in colour and black & white.