Perhaps you should try some spelling variations:
hien manh » hien hanh, tien manh, hieu manh
anh trinh » hanh trinh, anh tinh, thanh trinh
tong cong » trong cong, cong cong, dung cong
cong sat » cong suat, cong san, cong hat
phan dau » phan tu
hang dau » hang va, hang tai
va tong » va thong, va tuong, va trong

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc hien manh - ((anh trinh) or (canh tranh)) va tong cong sat ((phan dau) or (hang dau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hien manh - ((anh trinh) OR (canh tranh)) va tong cong sat ((phan dau) OR (hang dau)).
• Adding a wildcard symbol may retrieve word variants: hoc hien manh - ((anh trinh) or (canh tranh)) va tong cong sat ((phan dau) or (hang dau))*.