Carnivore-specific stable isotope variables and variation in the foraging ecology of modern and ancient wolf populations: case studies from Isle Royale, Minnesota, and La Brea. Canadian Journal of Zoology. 85(4):458-471.. 2007.
Stable isotopes, ecological integration and environmental change: wolves record atmopsheric carbon isotope trend better than tree rings. Proceedings of the Royal Society of London B. 274(1624):2471-2480.. 2007.