Perhaps you should try some spelling variations:
control problems » control program (Expand search)
tree complexity » the complexity (Expand search), time complexity (Expand search), tone complexity (Expand search)
coupling python » coupling protein (Expand search)
using coupling » running coupling (Expand search), using competing (Expand search), using coupled (Expand search)
python python » pythons python (Expand search), piton python (Expand search), pitons python (Expand search)
coder tree » modern tree (Expand search), under tree (Expand search), poder tres (Expand search)

You may be able to get more results by adjusting your search query.

• Removing quotes may allow a broader search: (( coder tree complexity control problems ) OR ( using coupling python python programming ))~.