Perhaps you should try some spelling variations:
trinh nghien » trinh nghe, kinh nghiem, trinh thiet
trinh thien » trinh thiet, trinh tin, trinh thi
hanh trinh » canh tranh, hanh chinh
nghien dan » nghiep dan, nghe dan, nghia dan
trinh tien » trinh tieng, trinh tin, trinh dien
danh hoc » dan hoc, danh hoa, anh hoc
tu hanh » du hanh, lu hanh, thi hanh

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( tu hanh trinh nghien dan toc ) or ( thuc hanh ((trinh thien) OR (trinh tien)) danh hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu hanh trinh nghien dan toc ) OR ( thuc hanh ((trinh thien) OR (trinh tien)) danh hoc )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tu hanh trinh nghien dan toc ) or ( thuc hanh ((trinh thien) OR (trinh tien)) danh hoc ))".
• Adding a wildcard symbol may retrieve word variants: (( tu hanh trinh nghien dan toc ) or ( thuc hanh ((trinh thien) OR (trinh tien)) danh hoc ))*.