1971. 4th edition. 502 pages. Green and white pictorial dust jacket over green cloth. Pages are lightly tanned and thumbed at the edges, with light foxing. Binding has remained firm. Boards are a little rub worn with slight shelf wear to corners, spine and edges. Corners are a little bumped and spine ends are a mildly crushed. Tanning to spine and edges. The unclipped dust jacket has moderate edge wear, tears and chips to edges and spine ends. Tanning to spine and edges. Water marks to edges and corners.