Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
dau dai » dat dai, sau dai, dau da
loc va » hoc va
luc va » duc va, tuc va
cua te » cua tu
sach v » sach va, sach y, sach 2
va cao » va cac, va dao, va bao
v nang » va nang, vu nang, van nang
x hoi » xa hoi, o hoi, x ho
va co » vo co

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 cao) or (va co)) ((luc va) OR (loc va)) dau dai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach v nang x hoi. hieu ((va cao) OR (va co)) ((luc va) OR (loc va)) dau dai cua te*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach v nang x hoi. hieu ((va cao) or (va co)) ((luc va) OR (loc va)) dau dai cua te*".