Ghirardi G. (1999)The Dynamical Reduction Program: An Example of a Quantum Theory without Observers. Em: Greenberger D., Reiter W.L., Zeilinger A. (eds) Epistemological and Experimental Perspectives on Quantum Physics. Vienna Circle Institute Yearbook [1999] (Institut ‘Wiener Kreis’ Society for the Advancement of the Scientific World Conception), vol 7. Springer, Dordrecht