Perhaps you should try some spelling variations:
"do mot chieu snippets" » "do mot code snippets", "do mot chien snippets", "do doi chieu snippets", "do ho chieu snippets", "o mot chieu snippets", "do moi chieu snippets", "bo mot chieu 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: (((("do mot chieu snippets") or ("python using java snippets"))) or ("locating bug core snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("do mot chieu snippets") OR ("python using java snippets"))) OR ("locating bug core snippets")).
• Removing quotes may allow a broader search: (((( do mot chieu snippets ) or ( python using java snippets ))) or ( locating bug core snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("do mot chieu snippets") or ("python using java snippets"))) or ("locating bug core snippets"))*.