Perhaps you should try some spelling variations:
trinh thiet » trinh viet, trinh thi
qua danh » luan danh, luat danh, quoc danh
dien han » dien phan, dien than, dien ban
dien dan » hien dai, vien dai, gian dan
qua dan » qua ban, cua dan, mua dan
viet va » viet van, viet ha, tiet va
va hoc » van 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 ((qua danh) OR (qua dan)) cua nguoi viet va hoc ((dien han) or (dien dan))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: giao trinh thiet ((qua danh) OR (qua dan)) cua nguoi viet va hoc ((dien han) OR (dien dan)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "giao trinh thiet ((qua danh) OR (qua dan)) cua nguoi viet va hoc ((dien han) or (dien dan))".
• Adding a wildcard symbol may retrieve word variants: giao trinh thiet ((qua danh) OR (qua dan)) cua nguoi viet va hoc ((dien han) or (dien dan))*.