Perhaps you should try some spelling variations:
"dong trinh hoa snippets" » "cong trinh hoa snippets", "dong tinh hoa snippets", "dong tranh hoa snippets", "dong trinh do snippets", "dong trinh han snippets"
"data using java snippets" » "data using data 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: (((("dong trinh hoa snippets") or ("data using java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("dong trinh hoa snippets") OR ("data using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( dong trinh hoa snippets ) or ( data using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dong trinh hoa snippets") or ("data using java snippets"))) or ("locating bug code snippets"))*.