Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets"
"thi luan so snippets" » "thi lan so snippets", "thi xuan so snippets", "thi loan so snippets", "thi luat so snippets", "thi quan so snippets", "thi luan san 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: (((("thi luan so snippets") or ("python using java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("thi luan so snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( thi luan so snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("thi luan so snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.