Perhaps you should try some spelling variations:
"doi tan doan snippets" » "doi tan code snippets", "doi tran doan snippets", "doi tap doan snippets", "doi van doan snippets", "doi ban doan snippets", "doi tac doan snippets", "dai tan doan snippets"
"locating bug core snippets" » "locating bug code snippets"
"python using java snippets" » "python using data 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 snippets") or ("doi tan doan snippets"))) or ("locating bug core snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("python using java snippets") OR ("doi tan doan snippets"))) OR ("locating bug core snippets")).
• Removing quotes may allow a broader search: (((( python using java snippets ) or ( doi tan doan snippets ))) or ( locating bug core snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("python using java snippets") or ("doi tan doan snippets"))) or ("locating bug core snippets"))*.