Herbert L. Calhoun

The Management and Analysis of International Event Data: A Computerized System for Monitoring and Projecting Event Flows.

Charles A. McClelland, Rodney G. Tomlinson, Ronald G. Sherwin, 1971 .

STRUCTURE OF A METHODOLOGY FOR ENVIRONMENTAL PROJECTIONS.

Herbert L. Calhoun, Robert A. Young, Dimitry N. Ivanoff, 1967 .