Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets"
"doc van cau snippets" » "do van cau snippets", "hoc van cau snippets", "duc van cau snippets", "doc van dau snippets", "doc van hau snippets", "doc van chat snippets"
"locating bug code snippets" » "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: (((("doc van cau snippets") or ("python using java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("doc van cau snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( doc van cau snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("doc van cau snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.