Perhaps you should try some spelling variations:
2c mechatronics » etc mechatronics, _ mechatronics, 1 mechatronics
c mechatronics » _ mechatronics, 1 mechatronics, a mechatronics
2c robotics » 26 robotics, c robotics, 2.1 robotics
29 robotics » 9 robotics, 19 robotics, 26 robotics
21 robotics » 2.1 robotics, 1 robotics, 11 robotics
2 robotics » _ robotics, 6 robotics, 5 robotics
26 robotic » 6 robotic, 22 robotic, 16 robotic
2 robotic » 12 robotic, _ robotic, 3 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 (21 robotics))) OR (2 robotics))) OR (((((26 robotic) OR (2 robotic))s) OR (((26 robotic) OR (2 robotic))))))%((2c mechatronics) OR (c mechatronics))%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%22control%((((((((2c robotics) OR (29 robotics))) or (21 robotics))) or (2 robotics))) or (((((26 robotic) or (2 robotic))s) or (((26 robotic) or (2 robotic))))))%((2c mechatronics) or (c mechatronics))%22".
• Adding a wildcard symbol may retrieve word variants: %22control%((((((((2c robotics) OR (29 robotics))) or (21 robotics))) or (2 robotics))) or (((((26 robotic) or (2 robotic))s) or (((26 robotic) or (2 robotic))))))%((2c mechatronics) or (c mechatronics))%22*.