Dan Yakir, Arie Issar et al., “13C and 18O of Wood from the Roman Siege Rampart in Masada, Israel (AD 70–73): Evidence for a Less Arid Climate for the Region,” Geochimica et Cosmochimica Acta 58 (1994), pp. 3535–3539. See also Arie S. Issar and Dan Yakir, “Isotopes from Wood Buried in the Roman Siege Ramp of Masada: The Roman Period’s Colder Climate,” The Biblical Archaeologist 60 (1997), pp. 101–106.