Perhaps you should try some spelling variations:
optimization problems » optimization problem, optimization models
problems developing » problems development, peoples developing, process developing
module programming » modular programming, model programming, focused programming
code programming » cone programming, model programming, scope programming

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: optimization problems developing ((module programming) OR (code programming)).~.
• Adding a wildcard symbol may retrieve word variants: optimization problems developing ((module programming) or (code programming)).*.