Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets"
"den le toan snippets" » "den ke toan snippets", "den le doan snippets", "den le tuan snippets", "den led toan snippets", "yen le toan snippets"
"locating bug code snippets" » "locating bung code snippets", "locating bugs code snippets", "locating bug core snippets"

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (((("den le toan snippets") or ("python using java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("den le toan snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( den le toan snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("den le toan snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.