Perhaps you should try some spelling variations:
"dong tac doan phan." » "cong tac doan phan." (Expand Search), "dong tai doan phan." (Expand Search), "dong bac doan phan." (Expand Search), "dong tap doan phan." (Expand Search), "dong tac toan phan." (Expand Search)
"dong tac dan phan." » "cong tac dan phan." (Expand Search), "dong tai dan phan." (Expand Search), "dong bac dan phan." (Expand Search), "dong tac dan phap." (Expand Search), "dong tac dam phan." (Expand Search), "dong tac van phan." (Expand Search), "dong sac dan phan." (Expand Search), "dong tac ban phan." (Expand Search)
"dong cac dan phan." » "dong cac dan phap." (Expand Search), "dong cac dam phan." (Expand Search), "dong cac van phan." (Expand Search), "dung cac dan phan." (Expand Search), "dong bac dan phan." (Expand Search), "trong cac dan phan." (Expand Search)

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 tac doan phan.") OR ((("dong tac dan phan.") OR ("dong cac dan phan."))))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"dong tac doan phan.\") OR (((\"dong tac dan phan.\") OR (\"dong cac dan phan.\"))))".
• Removing quotes may allow a broader search: (( dong tac doan phan. ) OR ((( dong tac dan phan. ) OR ( dong cac dan phan. )))).
• Adding a wildcard symbol may retrieve word variants: (("dong tac doan phan.") OR ((("dong tac dan phan.") OR ("dong cac dan phan."))))*.