Perhaps you should try some spelling variations:
rotational invariant » rotationally invariant, rotational invariance, rotation invariant
rotatory inertia » rotary inertia, rotational inertia
rotor inertia » rotary inertia, monitor inertia, motion inertia

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: ((rotor inertia) OR (((rotatory inertia) OR (rotational invariant)))).
• Adding a wildcard symbol may retrieve word variants: ((rotor inertia) or (((rotatory inertia) or (rotational invariant))))*.