Perhaps you should try some spelling variations:
trinh thiet » trinh viet, trinh thi
vien than » vien thanh, dien than, vien nhan
mua danh » qua danh, luan danh, cua doanh
dien han » dien phan, dien than, dien dan
mua dan » cua dan, mua ban, cua dang
viet ha » viet nam
ha hoc » hoa hoc, nha hoc, va hoc

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 thiet ((mua danh) or (mua dan)) cua nguoi viet ha hoc ((dien han) or (vien than))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: giao trinh thiet ((mua danh) OR (mua dan)) cua nguoi viet ha hoc ((dien han) OR (vien than)).
• Adding a wildcard symbol may retrieve word variants: giao trinh thiet ((mua danh) or (mua dan)) cua nguoi viet ha hoc ((dien han) or (vien than))*.