Perhaps you should try some spelling variations:
2c mechatronics » etc mechatronics, _ mechatronics, 1 mechatronics
c mechatronics » _ mechatronics, 1 mechatronics, a mechatronics
2.1 robotics » 1.1 robotics, 2.5 robotics, 3.1 robotics
2c robotics » 29 robotics, c robotics, 2.5 robotics
21 robotics » 11 robotics, 21 robotic, 29 robotics
26 robotics » 6 robotics, 26 robotic, 16 robotics
2 robotics » _ robotics, a robotics, 2 robotic

Try widening your search to All Fields.

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: %22control%((((((2c robotics) OR (((21 robotics) OR (2.1 robotics))))) OR (2 robotics))) OR (26 robotics))%((2c mechatronics) OR (c mechatronics))%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%22control%((((((2c robotics) or (((21 robotics) OR (2.1 robotics))))) or (2 robotics))) or (26 robotics))%((2c mechatronics) or (c mechatronics))%22".
• Adding a wildcard symbol may retrieve word variants: %22control%((((((2c robotics) or (((21 robotics) OR (2.1 robotics))))) or (2 robotics))) or (26 robotics))%((2c mechatronics) or (c mechatronics))%22*.