Filley, T. R., McCormick, Melissa K., Crow, S. E., Szlavecz, K., Whigham, Dennis F., Johnston, C. T., and van den Heuvel, R. N. 2008. "
Comparison of the chemical alteration trajectory of Liriodendron tulipifera L. leaf litter among forests with different earthworm abundance."
Journal of Geophysical Research. G. Biogeosciences. 113:G01027.