Perhaps you should try some spelling variations:
trinh nhiet » trinh thiet, trinh nghien, trinh viet
luan danh » luan thanh, luan van, luan san
luan nang » luan van, van nang, luan san
cho nguoi » cua nguoi
hoc tieng » hoc hien
hoc tien » hoc hien, hoc vien, hoc tren
viet nm » viet nam, viet nami, viet anh

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 nhiet ((luan danh) or (luan nang)) cho nguoi viet nm ((hoc tien) OR (hoc tieng)) duan~.
• If you are trying to use Boolean operators, they must be ALL CAPS: giao trinh nhiet ((luan danh) OR (luan nang)) cho nguoi viet nm ((hoc tien) OR (hoc tieng)) duan.
• The words AND, OR and NOT may confuse the search; try adding quotes: "giao trinh nhiet ((luan danh) or (luan nang)) cho nguoi viet nm ((hoc tien) OR (hoc tieng)) duan".
• Adding a wildcard symbol may retrieve word variants: giao trinh nhiet ((luan danh) or (luan nang)) cho nguoi viet nm ((hoc tien) OR (hoc tieng)) duan*.