An electronic book on a computer readable medium, e.g., a CD or the like, has “real-life” pre-recorded audio (preferably, in MP3 format) and visual text (preferably, in RTF format) seamlessly linked together via a linking file (preferably, in XML format) such that a reader can switch back and forth...http://www.google.de/patents/US20070005616?utm_source=gb-gplus-sharePatent US20070005616 - System and method for the delivery of electronic books
