Fifty-first Edition. 400 pages. No dust jacket. Green cloth boards with lettering. Clean pages with light tanning and mild foxing throughout. More pronounced to free endpapers and pastedowns. Pen markings to front free endpaper. Binding remains firm. Boards have mild edge-wear with slight rubbing to surfaces and bumping to corners. Lettering is darkened. Book has a slight forward lean. Visible wear marks to boards.