- Perumanl, P. A., J. R. Purdy, and D. N. Roy. 1981. Distribution of Dursban 4E on mature elm trees sprayed by hydraulic sprayer and mist blower. Pages 466-473 in E. S. Kondo, Y. Hiratsuka, and W. B. G. Denyer (eds.), Proceedings Dutch elm disease symposium and workshop, 5-9 October 1981. Canada Department of the Environment, Canadian Forestry Service and Province of Manitoba, Department of Natural Resources. 517 p.
- Roy, D. N., J. R. Purdy, P. A. Perumal, and J. K. Grace. 1988. Effect of application equipment on the distribution of chlorpyrifos applied for Dutch elm disease vector control . Entomological Society of Ontario, Proceedings 119:63-68.