E. Brynjolfsson, и L. Hitt. The Puzzling Relations Between Computer and the
Economy, стр. 9--20. Cambridge, MIT Press, (2001)http://grace.wharton.upenn.edu/~lhitt/jep.pdf
and http://ebusiness.mit.edu/Erik/JEP Beyond
Computation 9-20.pdf -- visited 3$^rd$~July~2004.
E. Brynjolfsson, и L. Hitt. Journal of Economic Perspectives, 14 (4):
23--48(2000)http://grace.wharton.upenn.edu/~lhitt/jep.pdf
and http://ebusiness.mit.edu/Erik/JEP Beyond
Computation 9-20.pdf -- visited 3$^rd$~July~2004.