Perhaps you should try some spelling variations:
thanh di » thanh doi, thanh de, thanh do
te sach » toc sach
hieu va » lieu va, hieu qua
va cam » va cham, va cac, va cao
sach v » sach va, sach y, sach 2
luc va » duc va, loc va
tuc va » thuc va, truc va, tuc xa
v nang » va nang, vu nang, van nang
di cua » dai cua, doi cua, de cua
cua te » cua tu
x hoi » xa hoi, o hoi, 5 hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach v nang ((x hoi) OR (x ho)). hieu va cam ((luc va) or (tuc va)) thanh di cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach v nang ((x hoi) OR (x ho)). hieu va cam ((luc va) OR (tuc va)) thanh di cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach v nang ((x hoi) OR (x ho)). hieu va cam ((luc va) or (tuc va)) thanh di cua te".
• Adding a wildcard symbol may retrieve word variants: te sach v nang ((x hoi) OR (x ho)). hieu va cam ((luc va) or (tuc va)) thanh di cua te*.