Perhaps you should try some spelling variations:
"pesticides routes / diffusion rate / testing" » "pesticides computer / diffusion rate / testing", "pesticides updates / diffusion rate / testing", "pesticides ddts / diffusion rate / testing"
"pesticides acute / diffusion rate / testing" » "pesticides action / diffusion rate / testing", "pesticides a / diffusion rate / testing", "pesticides all / diffusion rate / testing"
"pesticides role / diffusion rate / testing" » "pesticides risk / diffusion rate / testing", "pesticides food / diffusion rate / testing", "pesticides recent / diffusion rate / testing"

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (("pesticides acute / diffusion rate / testing") OR ((("pesticides routes / diffusion rate / testing") OR ("pesticides role / diffusion rate / testing")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"pesticides acute / diffusion rate / testing\") or (((\"pesticides routes / diffusion rate / testing\") OR (\"pesticides role / diffusion rate / testing\"))))".
• Removing quotes may allow a broader search: (( pesticides acute / diffusion rate / testing ) or ((( pesticides routes / diffusion rate / testing ) OR ( pesticides role / diffusion rate / testing )))).
• Adding a wildcard symbol may retrieve word variants: (("pesticides acute / diffusion rate / testing") or ((("pesticides routes / diffusion rate / testing") OR ("pesticides role / diffusion rate / testing"))))*.