By McCallum, Bennett T.
By McKinnon, Ronald I
By Subacchi, Paola
By Chapman, Colin
By Heinz Riehl, Rita M. Rodriguez
By Tapscott, Don, Alex
By Grubel, Herbert G.
By De Grauwe, Paul
By Frydman, Roman, Goldberg, Michael D., Phelps, Edmund S.
By Madura, Jeff
By Aljandali, Abdulkader M.
By Carroll, Terry
By Arndt, Sven W., etc.