1978. Twenty-Seventh Edition. 254 pages. Pictorial dust jacket over blue cloth. Contains black and white photographs. Bright and clean pages with light tanning to text block edges. Binding is firm throughout with mild thumb-marking. Sticker to front pastedown. Boards have light shelf-wear with corner bumping. Mild sunning to spine and board edges. Mild crushing to spine ends. Unclipped jacket has light edgewear with tears and creasing. Mild foxing. Heavy tanning to spine and edges. Mild rubbing and marking all over.