The major components of the International Futures (IFs) modeling system are extensively documented in working papers, and documentation of any given component is updated at intervals to reflect additions and refinements as well as connections to other system components. Because of its evolving nature, it is important to note working paper numbers and dates when using and citing model documentation.
Hughes, Barry B. 2001. “Global Social Transformation: The Sweet Spot, the Steady Slog, and the Systemic Shift.” Economic Development and Cultural Change 49 (2): 423–458.
Full Citation: Hughes, B. B. (1988). International futures (IFs): History and status. Social Science Computer Review, 6(1), 43–48. http://ssc.sagepub.com/content/6/1/43.full.pdf+html