Perhaps you should try some spelling variations:
"coder coder site allocation problem" » "coder coder site location problem" (Expand search), "coder coder state allocation problem" (Expand search), "coder coder time allocation problem" (Expand search), "coder decoder site allocation problem" (Expand search), "code code site allocation problem" (Expand search), "decoder codec site allocation problem" (Expand search), "coder copper site allocation problem" (Expand search), "coder boer site allocation problem" (Expand search), "coder code size allocation 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.

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"coder coder site allocation problem\") OR (\"_ python python python programming\"))~".
• Removing quotes may allow a broader search: (( coder coder site allocation problem ) OR ( _ python python python programming ))~.
• Adding a wildcard symbol may retrieve word variants: (("coder coder site allocation problem") OR ("_ python python python programming"))*.