Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets"
"duc van que snippets" » "duc va que snippets", "duc tan que snippets", "duc manh que snippets", "duc van quy snippets", "duc van due snippets", "duc van hue 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: (((("duc van que snippets") or ("python using java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("duc van que snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( duc van que snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("duc van que snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.