Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
thong cong » trong cong, tong cong, thong thong
thuong con » thuong dong, truong cong, thuong chi
hoc chiet » hoc nhiet, hoc hien, hoc viet
hoc thiet » hoc thieu, hoc thuyet, hoc hien
trinh ca » trinh cau, trinh cua, trinh cac
dan chan » dan gian, dan ca, van chat
doan » doanh, toan, soan

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((hoc chiet) OR (hoc thiet)) tach - hanh trinh ca ((thong cong) or (thuong con)) dan chan doan~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc chiet) OR (hoc thiet)) tach - hanh trinh ca ((thong cong) OR (thuong con)) dan chan doan.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((hoc chiet) OR (hoc thiet)) tach - hanh trinh ca ((thong cong) or (thuong con)) dan chan doan".
• Adding a wildcard symbol may retrieve word variants: ((hoc chiet) OR (hoc thiet)) tach - hanh trinh ca ((thong cong) or (thuong con)) dan chan doan*.