Karen Blixen and Julian Barnes both used pseudonyms in their works.
Karen Blixen Baroness Karen Christenze von Blixen-Finecke (née Dinesen; 17 April 1885 – 7 September 1962) was a Danish author who wrote works in Danish and English. She is best known under her pen names Isak Dinesen, used in English-speaking countries, and Tania Blixen, used in German-speaking countries. She also published works using the aliases Osceola and Pierre Andrézel.
A. S. M. Hutchinson Arthur Stuart-Menteth Hutchinson (2 June 1879 – 14 March 1971), commonly known by his initials A. S. M. Hutchinson, was a British novelist.