Haffner, P. (2001). The mystery of reason. Gracewing.
Cita Chicago Style (17a ed.)Haffner, Paul. The Mystery of Reason. Leominster: Gracewing, 2001.
Cita MLA (9a ed.)Haffner, Paul. The Mystery of Reason. Gracewing, 2001.
Precaución: Estas citas no son 100% exactas.