Perhaps you should try some spelling variations:
hieu viec » nhieu viec, hieu ve, sieu viet
sach nuoc » sach duoc, cac nuoc, bach tuoc
hieu van » hieu va, thien van, lieu va
danh doi » danh di, thanh doi, dung doi
su sach » so sach, vu sach
doi cua » dai cua, hoi cua
va danh » va dinh, va dan, va hanh
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa

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 xa) OR (nang ma)) hoi. ((hieu viec) or (hieu van)) sach nuoc va danh doi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((nang xa) OR (nang ma)) hoi. ((hieu viec) OR (hieu van)) sach nuoc va danh doi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky ((nang xa) OR (nang ma)) hoi. ((hieu viec) or (hieu van)) sach nuoc va danh doi cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang xa) OR (nang ma)) hoi. ((hieu viec) or (hieu van)) sach nuoc va danh doi cua tre*.