Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets"
"den hieu hoc snippets" » "de hieu hoc snippets", "den hien hoc snippets", "ten hieu hoc snippets", "den lieu hoc snippets", "den hieu hoa snippets", "den tieu hoc 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 hieu hoc 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 hieu hoc snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( den hieu hoc snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("den hieu hoc snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.