Perhaps you should try some spelling variations:
"python missing data snippets" » "python using data snippets"
"locating bug core snippets" » "locating bug code snippets"
"toan du 3 snippets" » "tran duc 3 snippets", "toan cau 3 snippets", "toan du _ snippets", "toan do 3 snippets", "toan du f snippets"

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((("toan du 3 snippets") OR ("python missing data snippets"))) OR ("locating bug core snippets"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"toan du 3 snippets\") OR (\"python missing data snippets\"))) OR (\"locating bug core snippets\"))".
• Removing quotes may allow a broader search: (((( toan du 3 snippets ) OR ( python missing data snippets ))) OR ( locating bug core snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("toan du 3 snippets") OR ("python missing data snippets"))) OR ("locating bug core snippets"))*.