Perhaps you should try some spelling variations:
covariation problem » variation problem (Expand search), nonvariational problem (Expand search), coordination problem (Expand search)
coding covariation » coding variation (Expand search), considering covariations (Expand search)
coding coding » coding decoding (Expand search), coding using (Expand search), coding canine (Expand search)
python python » pythons python (Expand search), piton python (Expand search), pitons python (Expand search)
coder coding » modern coding (Expand search), color coding (Expand search), odor coding (Expand search)

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "(( coder coding coding covariation problem ) OR ( python python python python programming ))~".
• Adding a wildcard symbol may retrieve word variants: (( coder coding coding covariation problem ) OR ( python python python python programming ))*.