Two online papers
The following were linked from the Centauri Dreams post on this subject.
The Houtkooper and Schulze-Makuch paper “A Possible Biogenic Origin for Hydrogen Peroxide on Mars: The Viking Results Reinterpretedâ€:
http://arxiv.org/pdf/physics/0610093
Gilbert Levin’s 1997 paper “The Viking Labeled Release Experiment and Life on Mars,†SPIE Proceedings of “Instruments, Methods, and Missions for the Investigation of Extraterrestrial Microorganisms,†(29 July-1 August 1997):
http://mars.spherix.com/spie/spiehtml.htm