Perhaps you should try some spelling variations:
"quantum dynamical system" » "quantum dynamics system", "quantum chemical system"
"quantum dynamical systems" » "quantum dynamics systems", "quantum chemical systems"
"random dynamic systems" » "random economic systems", "random dynamics systems", "random dynamical systems", "freedom dynamic systems"

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 dynamical system") OR ("quantum dynamical systems"))) OR ("random dynamic systems")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"quantum dynamical system\") OR (\"quantum dynamical systems\"))) or (\"random dynamic systems\"))".
• Removing quotes may allow a broader search: (((( quantum dynamical system ) OR ( quantum dynamical systems ))) or ( random dynamic systems )).
• Adding a wildcard symbol may retrieve word variants: (((("quantum dynamical system") OR ("quantum dynamical systems"))) or ("random dynamic systems"))*.