Perhaps you should try some spelling variations:
"differentes dynamical systems" » "different dynamical systems", "differences dynamically systems", "differential dynamical systems"
"differential dynamic systems" » "differentiable dynamical systems", "differential delay systems"
"different economic systems" » "different economic sectors"

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: (("differentes dynamical systems") OR ((("differential dynamic systems") OR ("different economic systems")))).
• Removing quotes may allow a broader search: (( differentes dynamical systems ) or ((( differential dynamic systems ) or ( different economic systems )))).
• Adding a wildcard symbol may retrieve word variants: (("differentes dynamical systems") or ((("differential dynamic systems") or ("different economic systems"))))*.