DAG HAMMARSKJOLD(1905 - 1961) Swedish diplomat and Secretary-General of the United Nations. Died under mysterious circumstances in a Congo air mishap. He was awarded, posthumously, the 1961 Nobel Peace Prize. Fine content T.L.S. "with kind regards Dag Hammarskjold" as Secretary-General on official letterhead, 1p. 4to., New York, Mar. 31, 1959, to Polish Ambassador Jerzy Michalowski, in part: "...Upon my return to Headquarters I found your letter...together with the books by Mme. Maria Dabrowska which you so kindly left in my office...I have sent the German edition of her 'Nights and Days' on to interested friends in Sweden...". Celebrated Polish author Maria Dabrowska (1889 - 1965) is best remembered for her works The Cherry Branch, The Signs of Life, as well as Nights and Days, published in 1932. Signed in bright blue ink, with original envelope, very good.