Ambrose, Stephen E. Undaunted Courage : Meriwether Lewis, Thomas Jefferson, and the opening of the American West - New York : Simon & Schuster, c1996. - 511 p. : ill., maps ; 25 cm. Includes bibliographical references (p. 493-496) and index. ISBN: 0684811073 LCCN: 95037146 Subjects--Personal Names: Lewis, Meriwether, 1774-1809. Clark, William, 1770-1838. Jefferson, Thomas, 1743-1826. Subjects--Meeting Names: Lewis and Clark Expedition (1804-1806) Subjects--Topical Terms: Explorers--Biography.--United States LC Class. No.: F592.7 / .A49 1996