Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets", "python using java slippers"
"van han viet snippets" » "van san viet snippets", "van van viet snippets", "van dan viet snippets", "van hanh viet snippets", "van phan viet snippets", "van nhan viet snippets", "van han viet 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: (((("van han viet snippets") or ("python using java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("van han viet snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( van han viet snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("van han viet snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.