Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
danh di » danh du, xanh di, danh dien
sach va » sach xa, sach ha, sach dao
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
va nang » van nang, da nang, cam nang
tuc va » thuc va, truc va, tuc xa
luc va » duc va, loc va
di cua » dai cua, doi cua, de cua
va cam » va cham, va cac, va cao
o hoi » co hoi, o hoc, o hai
x hoi » xa hoi, x ho, 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: thuoc sach va nang ((x hoi) or (o hoi)). hieu va cam ((luc va) OR (tuc va)) danh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach va nang ((x hoi) OR (o hoi)). hieu va cam ((luc va) OR (tuc va)) danh di cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach va nang ((x hoi) or (o hoi)). hieu va cam ((luc va) OR (tuc va)) danh di cua tre".
• Adding a wildcard symbol may retrieve word variants: thuoc sach va nang ((x hoi) or (o hoi)). hieu va cam ((luc va) OR (tuc va)) danh di cua tre*.