Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets"
"van tong son snippets" » "van thong son snippets", "van trong son snippets", "van tuong son snippets", "van dong son snippets", "van hong son snippets", "van tang son 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: (((("van tong 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: (((("van tong son snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( van tong son snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("van tong son snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.