Perhaps you should try some spelling variations:
"coder coder coverage control theory" » "coder code coverage control theory" (Expand search), "coder cancer coverage control theory" (Expand search), "coder center coverage control theory" (Expand search), "coder decoder coverage control theory" (Expand search), "code code coverage control theory" (Expand search), "decoder codec coverage control theory" (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.

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