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