Perhaps you should try some spelling variations:
dang thi » hoang thi, dang khoi
su sach » so sach, vu sach
cac dac » cac dan, cac dai, cac bac
thi cua » thai cua, thi cuc, tri cua
va dang » van dang, va nang, va lang
cac tuc » cac toc, cac tu, cac tac
hieu va » hieu qua
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet
sach 2 » sach y
2 nang » v nang

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 2 nang xa hoi. ((hieu va) or (lieu va)) ((cac tuc) or (cac dac)) va dang thi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach 2 nang xa hoi. ((hieu va) OR (lieu va)) ((cac tuc) OR (cac dac)) va dang thi cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach 2 nang xa hoi. ((hieu va) or (lieu va)) ((cac tuc) or (cac dac)) va dang thi cua tre*.