As the photos show, the cover and dust jacket have some yellowing, stains, and soiling, but the inside of the books is clean. These are rare books published in 1972 (Showa 42), 1976, and 1977. One book is from Shinchosha, and the remaining eight are published by Rodo Daigaku (Labor University). Since the binding is the same, I believe Rodo Daigaku took over from Shinchosha. I prefer to sell them as a set, but if you wish to purchase them individually, please buy at least three books. In that case, the price will be 600 yen per book.