Perhaps you should try some spelling variations:
"do duong van snippets" » "do duong va snippets", "do luong va snippets", "do dang van snippets", "doi duong van snippets", "do luong van snippets", "co duong van snippets", "do duong van slippers"
"using low java snippets" » "using low java slippers"
"locating bug code snippets" » "locating bug code slippers", "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: (((("do duong van snippets") or ("using low java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("do duong van snippets") OR ("using low java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( do duong van snippets ) or ( using low java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("do duong van snippets") or ("using low java snippets"))) or ("locating bug code snippets"))*.