Perhaps you should try some spelling variations:
"locating bug core snippets" » "locating bug code snippets"
"python using java snippets" » "python using data snippets"
"doc hai dung snippets" » "doc hai duong snippets", "doc mai dung snippets", "doc hai dang snippets", "hoc hai dung snippets", "do hai dung snippets", "duc hai dung 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 hai dung 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 hai dung snippets") OR ("python using java snippets"))) OR ("locating bug core snippets")).
• Removing quotes may allow a broader search: (((( doc hai dung snippets ) or ( python using java snippets ))) or ( locating bug core snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("doc hai dung snippets") or ("python using java snippets"))) or ("locating bug core snippets"))*.