Perhaps you should try some spelling variations:
nhieu viec » hieu viec, nhien viet
sach nuoc » sach duoc, cac nuoc, bach tuoc
dung doi » huong doi, dung tai, dung co
hieu van » hieu va, thien van, lieu va
cua tre » cua te, cuu tre, cua triet
doi cua » dai cua, hoi cua
su sach » so sach, vu sach
nang xa » nang x, lang xa, nang ma
va dung » van dung, va duong, vat dung
su sac » su cac, su xac

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