Turner, S. (1997). Net effects: a short history. In V. R. McKim & S. P. Turner (Eds.), Causality in crisis? Statistical methods and the search for causal knowledge in the social sciences. Indiana: University of Notre Dame Press.
Hughes, John A. & W. W. Sharrock (2007). Theory and methods in sociology: an introduction to sociological thinking and practice. Basingstoke, UK and N.Y.: Palgrave Macmillan.