Perhaps you should try some spelling variations:
toc sach » hoc sach, thuoc sach, nuoc sach
doc sach » hoc sach, nuoc sach, dac sac
lieu van » hieu van, sieu van, lieu nano
va thanh » gia thanh, ban thanh, va tinh
nang ma » tang ma, sang ma, nang cao
san cua » sang cua, ban cua, dan cua
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
ma hoi » mai hoi, xa hoi, ma hoa
cac su » cach su, cac sau, cac du
su va » su van, tu va

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (doc sach)) y nang ma hoi. ((lieu van) OR (lieu va)) cac su va thanh san cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) OR (doc sach)) y nang ma hoi. ((lieu van) or (lieu va)) cac su va thanh san cua tre~".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) OR (doc sach)) y nang ma hoi. ((lieu van) or (lieu va)) cac su va thanh san cua tre*.