A technique is provided for determining which pages of a selected magazine are read by a person acting as a test subject. Optic lenses are included which provide images of the magazine to a superimposing device. An image of the reader's eyes is also provided to the superimposing device so that the reader's...http://www.google.fr/patents/US4661847?utm_source=gb-gplus-shareBrevet US4661847 - Technique for monitoring magazine readers
