Input: concept: W E B Du Bois  answers:  ['Writings', 'The Souls of Black Folk', 'John Brown', 'The Negro', 'W.E.B. Du Bois on Asia', 'Darkwater', 'The world of W.E.B. Du Bois', 'The illustrated Souls of Black folk', 'The suppression of the African slave trade to the United States of America, 1638-1870', 'Dark princess']
Output: 

 what book did w.e.b. dubois wrote?