Complex sentence: Angelou returned to the same poem she based the title of "Caged Bird" upon for the title of "A Song Flung Up to Heaven," from the third stanza of the Paul Laurence Dunbar poem "Sympathy".
Split into simpler sentences: Angelou returned to the same poem she based the title of "Caged Bird" upon for the title of "A Song Flung Up to Heaven". As she had done in "Caged Bird", she used the third stanza of the Paul Laurence Dunbar poem "Sympathy".