This series contains primarily correspondence dealing with Hula's publications and includes correspondence with publishers, newspapers and periodicals, as well as colleagues. Individuals represented in the correspondence include colleagues at the New School for Social Research, such as Arnold Brecht, Eduard Heimann, Hans Simons and Hans Staudinger, as well as legal scholars and contemporaries such as Leo Gross, Hans Kelsen, Hans J. Morgenthau, Kurt Riezler, and Kurt von Fritz.