Bruxelles: Centre d'Etude de l'Energie Nucleaire C.E.N., 1959. Small 4to. Wraps. 23 p. R.1700. Warren Kaufman's copy, SIGNED by him at top of front cover. With a TLs to Warren stapled to a blank preliminary page. In the letter Baetsle states that he had found a mistake in a formula in a paper that he had written. Some residue from paper clip; else very good.