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