Perhaps you should try some spelling variations:
su sach » vu sach
thi cua » thai cua, thi cuc, tri cua
dan thi » dang thi, tran thi, dinh thi
cac tac » cac toc, cac bac, cac dac
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
so sach » so sanh, bo sach, co sach
nang xa » nang x, lang xa, nang ma
v nang » va nang, vu nang, van nang
va dan » ca dan, va dao, va dau
cac tu » cac thu, cach tu, cac du

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) OR (so sach)) v nang xa hoi. hieu va ((cac tu) or (cac tac)) va dan thi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sach)) v nang xa hoi. hieu va ((cac tu) OR (cac tac)) va dan thi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) OR (so sach)) v nang xa hoi. hieu va ((cac tu) or (cac tac)) va dan thi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((su sach) OR (so sach)) v nang xa hoi. hieu va ((cac tu) or (cac tac)) va dan thi cua tre*.