There is evidence that the methods of J. L. Moreno have held up respectably over time. Subsequent research from the University of Vienna shows the enormous influence that Moreno's theory of the Encounter ("Invitations to an Encounter", 1914) had on the development of Martin Buber's I-Thou philosophy, and Buber's influence on philosophy, theology, and psychology. His wife, Zerka Moreno, wrote: "While it is true that Buber broadened the idea of the Encounter, he did not create the instruments for it to occur." Moreno "produced the various instruments we now use for facilitating the human encounter, sociometry, group psychotherapy, psychodrama, and sociodrama". Zerka was herself an expert in psychodrama and sociometry, and continued her late husband's work.