Perhaps you should try some spelling variations:
trinh hieu » trinh thiet, trinh nhiet, trinh thien
trinh dieu » trinh dien, tinh dieu, trinh dinh
viet nami » viet nam, vien nam, viet nang
hoc tieng » hoc hien
tieng han » tieng anh
nami hoc » dai hoc, bai hoc, nang hoc
qua dan » qua danh, qua ban, cua dan

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

• Performing a fuzzy search may retrieve terms with similar spellings: giao ((trinh hieu) OR (trinh dieu)) qua dan ((cho nguoi) or (cua nguoi)) viet nami hoc tieng han~.
• If you are trying to use Boolean operators, they must be ALL CAPS: giao ((trinh hieu) OR (trinh dieu)) qua dan ((cho nguoi) OR (cua nguoi)) viet nami hoc tieng han.
• The words AND, OR and NOT may confuse the search; try adding quotes: "giao ((trinh hieu) OR (trinh dieu)) qua dan ((cho nguoi) or (cua nguoi)) viet nami hoc tieng han".
• Adding a wildcard symbol may retrieve word variants: giao ((trinh hieu) OR (trinh dieu)) qua dan ((cho nguoi) or (cua nguoi)) viet nami hoc tieng han*.