1. Mitchell, M. J., Mulligan, R. M., Hartenstein, R., & Neuhauser, E. F. (1977). Conversion of sludges in topsoil by earthworms. Compost Science, 18(4), 28–32.
2. Mitchell, M. J., Hornor, S. G., & Abrams, B. I. (1980). Decomposition of sewage sludge in drying beds and the potential role of the earthworm, Eisenia foetida. Journal of Environmental Quality., 9(3), 373–378.
3. Camp, Dresser and McKee, Inc. (1980). Compendium on solid waste management by vermicomposting. USA, Technical Report No. EPA-600/8-80-033, U.S. EPA, Municipal Environmental Research Laboratory, Cincinnati, OH, 72p.
4. Hornor, S. G., & Mitchell, M. J. (1981). Effect of the earthworm, Eisenia foetida (Oligochaeta), on fluxes of volatile carbon and sulfur compounds from sewage sludge. Soil Biology and Biochemistry., 13(5), 367–373.
5. Hartenstein, R. (1981). Utilization of earthworms and microorganisms in stabilization, decontamination and detoxification of residual sludges from treatment of wastewater. USA, Technical Report No. NSF/CEE-81009, National Science Foundation, Washington, DC, 19p.