Perhaps you should try some spelling variations:
"coder coder spatial diffusion problem" » "coder coder spatial dimension problem" (Expand search), "coder coder spatial decision problem" (Expand search), "coder coder fractional diffusion problem" (Expand search), "coder coder spatial diffusion process" (Expand search), "coder order spatial diffusion problem" (Expand search), "coder over spatial diffusion problem" (Expand search), "coder under spatial diffusion problem" (Expand search), "coder decoder spatial diffusion problem" (Expand search), "code code spatial diffusion problem" (Expand search), "decoder codec spatial diffusion problem" (Expand search)
"_ python python python programming" » "_ pythons python python programming" (Expand search), "_ piton python python programming" (Expand search), "_ pitons 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 spatial diffusion problem") OR ("_ python python python programming"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"coder coder spatial diffusion problem\") OR (\"_ python python python programming\"))".
• Removing quotes may allow a broader search: (( coder coder spatial diffusion problem ) OR ( _ python python python programming )).
• Adding a wildcard symbol may retrieve word variants: (("coder coder spatial diffusion problem") OR ("_ python python python programming"))*.