Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets"
"den tu cuong snippets" » "den thu cuong snippets", "den tu tuong snippets", "den tu cong snippets", "dien tu cuong snippets", "dan tu cuong snippets", "den su cuong 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: (((("den tu cuong snippets") or ("python using java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("den tu cuong snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( den tu cuong snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("den tu cuong snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.