Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets", "python using java slippers"
"don van sach snippets" » "don ban sach snippets", "don van hach snippets", "don ngan sach snippets", "doan van sach snippets", "dong van sach snippets", "do van sach snippets", "don van sach slippers"
"locating bug code snippets" » "locating bug code slippers", "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: (((("don van sach snippets") or ("python using java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("don van sach snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( don van sach snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("don van sach snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.