Complex sentence: Exceptions do exist, such as Robert Gunther's "Early Science in Oxford" and Edgar Allan Poe's "Tamerlane", but both of these books would be considered notable by virtue (for instance) of criterion 1.
Split into simpler sentences: Exceptions do exist, such as Robert Gunther's "Early Science in Oxford" or Edgar Allan Poe's "Tamerlane". Note however that both of these books would be considered notable by virtue (for instance) of criterion 1.