Note: Landsborough created May Fair Books Ltd and in 1962 its paperback imprint Armada Books, the latter for inexpensive children's books including many first paperback editions of decades-old fiction. Wikipedia lists or notes about 15 pseudonyms known to have been used by Landsborough as a writer. Library of Congress identifies six, chiefly Mike M'Cracken and names under which M'Cracken novels were reissued decades later with new titles.