Perhaps you should try some spelling variations:
canh trinh » hanh trinh, canh tinh, anh trinh
hien manh » hien hanh, tien manh, hieu manh
tong cong » trong cong, cong cong, dung cong
cong sat » cong suat, cong san, cong hat
sat hang » dat hang, mat hang, sat mang
hang dau » hang va, hang tai
he tong » he thong, he trong, he cong

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 - ((canh trinh) or (canh tranh)) he tong cong sat hang dau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hien manh - ((canh trinh) OR (canh tranh)) he tong cong sat hang dau.
• Adding a wildcard symbol may retrieve word variants: hoc hien manh - ((canh trinh) or (canh tranh)) he tong cong sat hang dau*.