Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets", "python using java slippers"
"van hoc ung snippets" » "van hoa ung snippets", "van hoc dung snippets", "van hoc cung snippets", "van hoc ung slippers"
"locating bug code snippets" » "locating bug code slippers", "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 hoc ung 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 hoc ung snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( van hoc ung snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("van hoc ung snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.