Perhaps you should try some spelling variations:
tien manh » tien anh, tien thanh, tieng anh
tranh van » tran van, trinh van, thanh van
hang cong » dang cong, hang nong, bang cong
hoc tien » hoc tieng, hoc hien, hoc vien
van hang » van khang, van hoang, van thang
cong san » cong tac
bac cau » bach cau, ba cau, bac can
van hau » van ha, van hai, van dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc tien manh - canh tranh van hang cong san ((bac cau) or (van hau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc tien manh - canh tranh van hang cong san ((bac cau) OR (van hau)).
• Adding a wildcard symbol may retrieve word variants: hoc tien manh - canh tranh van hang cong san ((bac cau) or (van hau))*.