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