1978. No Edition Remarks. Unpaginated. Pictorial jacket over brown cloth. Volume IV: paginated 936 to 1237. Contains diagrams and photographs in colour and black and white throughout. Maps to endpapers. Pages remain bright and clear. Binding is firm. Boards and spine have minimal shelf-wear, with minor corner bumping and crushing to ends. Unclipped jacket. Minimal edgewear with slight chipping to joints and spine ends.