Perhaps you should try some spelling variations:
"qua trinh do grippers" » "qua trinh soft grippers", "qua kinh do grippers", "qua trinh ky grippers"
"python using java slippers" » "python using data slippers", "python using java slippery"
"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: (((("python using java slippers") or ("qua trinh do grippers"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("python using java slippers") OR ("qua trinh do grippers"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( python using java slippers ) or ( qua trinh do grippers ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("python using java slippers") or ("qua trinh do grippers"))) or ("locating bug code snippets"))*.