Origine: The Dreams of Reason, 1988, ISBN 0-553-34710-1
Heinz Rudolf Pagels: Frasi in inglese
Origine: The Cosmic Code (1982), p. 312
Origine: The Cosmic Code (1982), p. 272
Origine: The Cosmic Code (1982), p. 271-272
Origine: The Cosmic Code (1982), p. 271
Origine: The Cosmic Code (1982), p. 312-313