Perhaps you should try some spelling variations:
"disease drug effectss." » "disease drug effectors.", "disease drugs effects.", "disease rug effects.", "disease drag effectss.", "disease drugs effectsss.", "disease xdrug effectsss."
"diseases drug effect." » "diseases drag effect.", "diseases drugs effects.", "diseases xdrug effects."
"diseases drug effects." » "diseases drag effects.", "diseases drugs effectss.", "diseases xdrug effectss."

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