Lot of four classic science fiction hardback books for young readers by John Christopher.  Includes: The Prince in Waiting, 1970 first printing; The Guardians, 1970 first printing; The Sword of The Spirits, 1972, appears to be second printing; and The White Mountains, 1968 second printing.  All are former library books with typical marks and stamps and reading wear, inside front page removed on some, in good minus to good condition as a set.  U. S. shipping and handling $6.50 in box, see payment details for additional payment information.  Thanks!