Perhaps you should try some spelling variations:
"diseases drag effects." » "diseases drug effects.", "diseases drugs effects.", "diseases dr effects.", "diseases xdrug effects.", "diseases rug effects.", "diseases dung effects.", "diseases drying effects.", "diseases zhang effects."
"diseases drag effect." » "diseases drug effect.", "diseases drugs effect.", "diseases dr effect.", "diseases dung effect.", "diseases drying effect.", "diseases zhang effect."
"diseases dag effect." » "diseases drug effect.", "diseases dale effect.", "diseases dogs effect.", "diseases dung effect.", "diseases zhang effect."

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: (("diseases drag effects.") OR ((("diseases drag effect.") OR ("diseases dag effect."))))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"diseases drag effects.\") or (((\"diseases drag effect.\") OR (\"diseases dag effect.\"))))~".
• Removing quotes may allow a broader search: (( diseases drag effects. ) or ((( diseases drag effect. ) OR ( diseases dag effect. ))))~.
• Adding a wildcard symbol may retrieve word variants: (("diseases drag effects.") or ((("diseases drag effect.") OR ("diseases dag effect."))))*.