Perhaps you should try some spelling variations:
variation functions » evaluation functions (Expand search), partition functions (Expand search), activation functions (Expand search)
coding variation » song variation (Expand search), coding variants (Expand search)
python python » pythons python (Expand search), piton python (Expand search), pitons python (Expand search)
code coding » code cloning (Expand search), code codigo (Expand search), code according (Expand search)
code code » code cdc (Expand search)

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

• Removing quotes may allow a broader search: (( code code coding variation functions ) OR ( api python python python programming ))~.