Sentence:  These sages include poet Carl Sandburg , statesman Jawaharlal Nehru and sculptor Jacques Lipchitz , in Volume One , and playwright Sean O'Casey , David Ben-Gurion , philosopher Bertrand Russell and the late Frank Lloyd Wright in the second <WSD>set</WSD> . 
Meaning of the word marked with <WSD> tags:  a group of things of the same kind that belong together and are so used