Complex sentence: Starting in 1914 he studied literature in St. Petersburg, and later, due to events of World War I and the Russian Revolution, in Moscow and lastly 1921 moved to Munich University, where he did receive Ph.D for doctoral thesis on Lithuanian folklore in 1924.
Split into simpler sentences: Starting in 1914 he studied literature in St. Petersburg, and later, due to the events of World War I and the Russian Revolution, in Moscow. In 1921 he moved to Munich University, where he received a Ph.D for a doctoral thesis on Lithuanian folklore in 1924.