Perhaps you should try some spelling variations:
trinh thiet » trinh thi
trinh viet » ninh viet, trinh vat
trien nhan » trien nha, tri nhan, trien khai
vien nhan » vien than, vien nganh, vien thanh
qua dinh » qua kinh, quy dinh, qua danh
dinh cua » dinh cuu, sinh cua, dinh cu
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) OR (trinh viet)) qua dinh cua nguoi viet ha hoc ((vien nhan) or (trien nhan))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: giao ((trinh thiet) OR (trinh viet)) qua dinh cua nguoi viet ha hoc ((vien nhan) OR (trien nhan)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "giao ((trinh thiet) OR (trinh viet)) qua dinh cua nguoi viet ha hoc ((vien nhan) or (trien nhan))".
• Adding a wildcard symbol may retrieve word variants: giao ((trinh thiet) OR (trinh viet)) qua dinh cua nguoi viet ha hoc ((vien nhan) or (trien nhan))*.