Perhaps you should try some spelling variations:
"coder coder variable diffusivity problem" » "coder coder variable diffusion problem" (Expand search), "coder coder variable diffusivity from" (Expand search), "coder under variable diffusivity problem" (Expand search), "coder color variable diffusivity problem" (Expand search), "coder mode variable diffusivity problem" (Expand search), "coder decoder variable diffusivity problem" (Expand search), "code code variable diffusivity problem" (Expand search), "decoder codec variable diffusivity problem" (Expand search)
"api python python python programming" » "api pythons python python programming" (Expand search), "api piton python python programming" (Expand search), "api pitons python python programming" (Expand search), "rpa python python python programming" (Expand search)

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("coder coder variable diffusivity problem") OR ("api python python python programming"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"coder coder variable diffusivity problem\") OR (\"api python python python programming\"))*".
• Removing quotes may allow a broader search: (( coder coder variable diffusivity problem ) OR ( api python python python programming ))*.