Perhaps you should try some spelling variations:
trinh thiet » trinh viet, trinh thi
trinh hieu » trinh dieu, trinh nhiet, trinh thien
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 dai » qua hai, cua dai, qua cai

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 thiet)) qua dai 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 thiet)) qua dai cua nguoi viet nami hoc tieng han.
• Adding a wildcard symbol may retrieve word variants: giao ((trinh hieu) or (trinh thiet)) qua dai cua nguoi viet nami hoc tieng han*.