Perhaps you should try some spelling variations:
hieu viec » nhieu viec, hieu ve, sieu viet
bach tuoc » sach duoc, sach nuoc
va triet » va thiet, va trien, ve triet
danh doi » danh di, thanh doi, dung doi
hieu van » hieu va, thien van, lieu va
sach ky » sac ky, sach y, sach ty
tuoc va » thuoc va, nuoc va, duoc va
va danh » va dinh, va dan, va hanh
nang ma » tang ma, sang ma, nang cao
cua tre » cua te, cuu tre, cua triet
su sach » so sach, vu sach
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 sach ky nang ma hoi. ((hieu viec) or (hieu van)) bach tuoc va danh doi ((cua tre) or (va triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang ma hoi. ((hieu viec) OR (hieu van)) bach tuoc va danh doi ((cua tre) OR (va triet)).
• Adding a wildcard symbol may retrieve word variants: su sach ky nang ma hoi. ((hieu viec) or (hieu van)) bach tuoc va danh doi ((cua tre) or (va triet))*.