1961. No Edition Stated. 65 pages. Paperback book with blue and white paper covers. Contains some black and white diagrams. Pages are lightly tanned and foxed, but text remains clear. Binding is firm. Paper covers have moderate shelf-wear, with noticeable curling to corners, and mild creasing.Moderate rubbing and scuffing to front cover, with noticeable marking to rear. Moderate scuffing and tearing to spine ends.