Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets", "python using java slippers"
"hoc dan van snippets" » "hoc dang van snippets", "hoc doan van snippets", "hoc dao van snippets", "hoc dan van 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: (((("hoc dan van snippets") or ("python using java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("hoc dan van snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( hoc dan van snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("hoc dan van snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.