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.
Maxwell Grant Maxwell Grant was a pen name used by the authors of "The Shadow" pulp magazine stories.