Otherwise, I just suggest one, which might not be written in the 20's.
1921: ANATOLE FRANCE (Thais)
1922: JACINTO BENAVENTE (Playwright; The Bonds of Interest)
1923: WILLIAM BUTLER YEATS (Playwright/Poet: Responsibilities and Other Poems)
1924: WLADYSLAW STANISLAW REYMONT for The Peasants.
1925: GEORGE BERNARD SHAW (Playwright: Pygmalion)
1926: GRAZIA DELEDDA (Elias Portolu)
1927: HENRI BERGSON (Philosopher: Creative Evolution)
1928: SIGRID UNDSET (I loved the Kristin Lavransdatter series!)
1929: THOMAS MANN for Buddenbrooks.