Olson, J. E., Bourne, E. G., & Columbus, C. (1967). The Northmen, Columbus and Cabot, 985-1503: The voyages of the Northman edited by Julius E. Olson [and] The voyages of Columbus and of John Cabot edited by Edward Gaylord Bourne. New York: Barnes & Noble.

Olson, Julius E.,, Edward Gaylord Bourne, and Christopher Columbus. The Northmen, Columbus and Cabot, 985-1503: The Voyages of the Northman Edited By Julius E. Olson [and] The Voyages of Columbus and of John Cabot Edited By Edward Gaylord Bourne. New York: Barnes & Noble, 1967.

Olson, Julius E.,, Edward Gaylord Bourne, and Christopher Columbus. The Northmen, Columbus and Cabot, 985-1503: The Voyages of the Northman Edited By Julius E. Olson [and] The Voyages of Columbus and of John Cabot Edited By Edward Gaylord Bourne. New York: Barnes & Noble, 1967.