Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets"
"hoc phan ct4 snippets" » "hoc dan ct4 snippets", "hoc pho ct4 snippets", "hoc phan tu snippets", "hoc phan cac snippets", "hoc phan co snippets"
"locating bug code snippets" » "locating bung code snippets", "locating bugs code snippets", "locating bug core snippets"

Try widening your search to All Fields.

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((("hoc phan ct4 snippets") or ("python using java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("hoc phan ct4 snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( hoc phan ct4 snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("hoc phan ct4 snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.