Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu va » hieu qua
cao suc » cao su, cao duc
dan dai » dat dai, can dai, dan dat
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang
suc va » duc va, tuc va, luc va
va dan » ca dan, va dao, va dau
cua te » cua tu
x hoi » xa hoi, o hoi, x ho

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach v nang x hoi. ((hieu va) or (lieu va)) cao suc va dan dai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach v nang x hoi. ((hieu va) OR (lieu va)) cao suc va dan dai cua te*.