Perhaps you should try some spelling variations:
thien danh » thien anh, thien dang, thien thanh
canh trinh » canh tranh, hanh trinh, canh tinh
hoc thien » hoc hien, hoc thieu, hoc thiet
hang cong » dang cong, hang nong, bang cong
trinh ve » trinh he, trinh va, trinh vi
cong san » cong tac
chan cau » can cau, chinh cau, nhanh cau
phan cau » phan dau, phan cac, phan tu
ve hang » ve hoang, ve chang, va hang

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 danh - canh trinh ve hang cong san ((chan cau) or (phan cau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thien danh - canh trinh ve hang cong san ((chan cau) OR (phan cau)).
• Adding a wildcard symbol may retrieve word variants: hoc thien danh - canh trinh ve hang cong san ((chan cau) or (phan cau))*.