Perhaps you should try some spelling variations:
thien thanh » tien thanh, thi thanh, hien hanh
hoc thien » hoc hien, hoc thieu, hoc thiet
tranh cuu » tranh cua, trinh cuu, tranh chua
nong cong » cong cong, tong cong, nang cong
bang cong » dang cong, bang song, hang cong
doan cau » toan cau, doan dau, doan cap
toan tap » toan ban

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc thien thanh - canh tranh cuu ((nong cong) or (bang cong)) tap ((doan cau) or (toan tap))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thien thanh - canh tranh cuu ((nong cong) OR (bang cong)) tap ((doan cau) OR (toan tap)).
• Adding a wildcard symbol may retrieve word variants: hoc thien thanh - canh tranh cuu ((nong cong) or (bang cong)) tap ((doan cau) or (toan tap))*.