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