 De Sola Pool translated and edited the Sephardic prayer book for the Union of Sephardic Congregations in 1954, and the Ashkenazic prayer book for the Rabbinical Council of America.These prayerbooks are still in use in congregations around the world.His book "The Kaddish" (1909, third printing 1964), based on his dissertation, remains a definitive and well-regarded work on the origins of the Kaddish prayer.