Perhaps you should try some spelling variations:
vpython colisoes » vpython collisions (Expand search)
colisoes python » colisoes proton (Expand search), codigos python (Expand search), colisoes eletron (Expand search)
decrease their » decrease the (Expand search), increase their (Expand search), decreases the (Expand search)
their decrease » the decrease (Expand search), their disease (Expand search), the decreased (Expand search)
python python » pythons python (Expand search), piton python (Expand search), pitons python (Expand search)
in program » in programs (Expand search)

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

• Removing quotes may allow a broader search: (( decrease their decrease in program ) OR ( vpython colisoes python python programming ))~.