Text this: A study of the Traité des indivisibles of Gilles Persone de Roberval : with a view to answering, insofar as is possible, the two questions: which propositions contained therein are his own, and which are due to his predecessors or contemporaries? and what effect, if any, had this work on his successors? / New York, Bureau of Publications, Teachers College, Columbia University, 1932.