Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
hanh tri » thanh tri, hanh tai, hanh trinh
ky tang » ky nang, ky dang, kho tang
tang ma » mang may, tang van
hieu ve » hieu van
hieu va » lieu va
duc van » duc va, duc tan, duc manh
cua tre » cua te, cuu tre, cua triet
su sac » su sach, su cac, su xac
sac ky » cac ky, sai ky
ma hoi » mai hoi, xa hoi, ma hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sac ky tang ma hoi. ((hieu ve) or (((hieu va) or (hieu qua)))) pham duc van hanh tri cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ky tang ma hoi. ((hieu ve) OR (((hieu va) OR (hieu qua)))) pham duc van hanh tri cua tre.
• Adding a wildcard symbol may retrieve word variants: su sac ky tang ma hoi. ((hieu ve) or (((hieu va) or (hieu qua)))) pham duc van hanh tri cua tre*.