Perhaps you should try some spelling variations:
2c mechatronics » c mechatronics, etc mechatronics, _ mechatronics
2c robotics » 21 robotics, c robotics, 2.1 robotics
29 robotics » 9 robotics, 19 robotics, 21 robotics
26 robotics » 26 robotic, 16 robotics, 21 robotics
6 robotics » _ robotics, 6 robotic, a robotics
2 robotics » _ robotics, a robotics, 2 robotic

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 (29 robotics))) OR (((((26 robotics) OR (6 robotics))) OR (2 robotics))))%2c mechatronics%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%22control%((((2c robotics) or (29 robotics))) or (((((26 robotics) OR (6 robotics))) or (2 robotics))))%2c mechatronics%22".
• Adding a wildcard symbol may retrieve word variants: %22control%((((2c robotics) or (29 robotics))) or (((((26 robotics) OR (6 robotics))) or (2 robotics))))%2c mechatronics%22*.