Perhaps you should try some spelling variations:
"phi van chen snippets" » "phi van code snippets", "phi van chien snippets", "phi yan chen snippets", "phi van chuyen snippets", "phi san chen snippets", "thi van chen snippets", "phi va chen snippets"
"locating bug core snippets" » "locating bug code snippets"
"python using java snippets" » "python using data 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: (((("python using java snippets") or ("phi van chen snippets"))) or ("locating bug core snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("python using java snippets") OR ("phi van chen snippets"))) OR ("locating bug core snippets")).
• Removing quotes may allow a broader search: (((( python using java snippets ) or ( phi van chen snippets ))) or ( locating bug core snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("python using java snippets") or ("phi van chen snippets"))) or ("locating bug core snippets"))*.