Perhaps you should try some spelling variations:
"quantum dynamic system" » "quantum dynamics system", "quantum dynamical system", "quantum ecodynamic system", "quantum dynamic systems", "quantum dynamical systems"
"random dynamics system" » "random dynamical system", "quantum dynamics system", "random dynamic systems", "random dynamisches system"

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: (("quantum dynamic system") OR ("random dynamics system")).
• Removing quotes may allow a broader search: (( quantum dynamic system ) or ( random dynamics system )).
• Adding a wildcard symbol may retrieve word variants: (("quantum dynamic system") or ("random dynamics system"))*.