Perhaps you should try some spelling variations:
"trinh toan code snippets" » "tinh toan code snippets", "thanh toan code snippets", "trinh han code snippets", "trinh toan co snippets", "trinh toan cong snippets", "trinh toan de snippets"
"dung cfd code snippets" » "dung cho code snippets", "dung cua code snippets", "dung co code snippets"
"locating bug core snippets" » "locating bug code snippets"

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (((("trinh toan code snippets") OR ("dung cfd code snippets"))) OR ("locating bug core snippets"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"trinh toan code snippets\") OR (\"dung cfd code snippets\"))) OR (\"locating bug core snippets\"))".
• Removing quotes may allow a broader search: (((( trinh toan code snippets ) OR ( dung cfd code snippets ))) OR ( locating bug core snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("trinh toan code snippets") OR ("dung cfd code snippets"))) OR ("locating bug core snippets"))*.