Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuoc sinh
thuat sach » thuat lanh, thuat san
va nang » van nang, da nang, cam nang
cao luc » bao luc, cao duc, cao suc
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
v nang » vu nang, van nang, voi nang
va cao » va cac, va co, va dao
luc va » duc va, tuc va, loc va
va dan » ca dan, va dao, va dau
dan de » dan den, dang de, van de
de cua » le cua, te cua, dieu cua
x hoi » xa hoi, o hoi, x ho

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) or (thuat sach)) ((v nang) OR (va nang)) x hoi. hieu va cao luc va dan de cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thuoc sach) OR (thuat sach)) ((v nang) OR (va nang)) x hoi. hieu va cao luc va dan de cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thuoc sach) or (thuat sach)) ((v nang) OR (va nang)) x hoi. hieu va cao luc va dan de cua tre".
• Adding a wildcard symbol may retrieve word variants: ((thuoc sach) or (thuat sach)) ((v nang) OR (va nang)) x hoi. hieu va cao luc va dan de cua tre*.