1976. Fourth Edition: Sixth Impression. 336 pages. Dust jacket over matching boards. Bright and clean pages with light tanning to text block edges. Binding is firm throughout with minor thumb-marking. Boards have light shelf-wear with corner bumping. Mild tanning to spine, which has mild crushing and wear to ends. Unclipped jacket has moderate edgewear with chips, tears, and creasing. Moderate tanning to spine. Light rubbing and marking all over.