Perhaps you should try some spelling variations:
"do vi toan snippets" » "do vi code snippets", "do va toan snippets", "do vi than snippets", "do bai toan snippets", "don vi toan snippets", "doc vi toan snippets", "do voi toan 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 ("do vi toan snippets"))) or ("locating bug core snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("python using java snippets") OR ("do vi toan snippets"))) OR ("locating bug core snippets")).
• Removing quotes may allow a broader search: (((( python using java snippets ) or ( do vi toan snippets ))) or ( locating bug core snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("python using java snippets") or ("do vi toan snippets"))) or ("locating bug core snippets"))*.