Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets"
"don van son snippets" » "doan van son snippets", "dong van son snippets", "do van son snippets", "don van dong snippets", "don van cong snippets", "don van sung 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: (((("don van son snippets") or ("python using java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("don van son snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( don van son snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("don van son snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.