Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
dan dat » dung dat, dong dat, dinh dat
dan dai » dat dai, can dai, dan da
cao tuc » dao tuc, cao duc, cao suc
hieu va » lieu va, hieu qua
va cao » va cac, va co, va dao
sach v » sach va, sach y, sach 2
tuc va » thuc va, truc va, tuc xa
nang o » nang co, nang ho, nang ro
v nang » va nang, vu nang, van nang
cua tu » cua tuc, cua su, cua cu
o hoi » co hoi, o hoc, o hai

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 o hoi. hieu va cao tuc va ((dan dai) or (dan dat)) cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach v nang o hoi. hieu va cao tuc va ((dan dai) OR (dan dat)) cua tu*.