Perhaps you should try some spelling variations:
"modern code in combinatorial problems" » "modern code _ combinatorial problems" (Expand search), "modern code of combinatorial problems" (Expand search), "modern code the combinatorial problems" (Expand search), "model code in combinatorial problems" (Expand search), "modern code and combinatorial problems" (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), "manim 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: "((\"modern code in combinatorial problems\") OR (\"api python python python programming\"))~".
• Removing quotes may allow a broader search: (( modern code in combinatorial problems ) OR ( api python python python programming ))~.
• Adding a wildcard symbol may retrieve word variants: (("modern code in combinatorial problems") OR ("api python python python programming"))*.