Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuoc sinh
thuat sach » thuat lanh, thuat san
cua tre » cua te, cuu tre, cua triet
v nang » va nang, vu nang, van nang
tuc va » thuc va, truc va, tuc xa
va dan » ca dan, va dao, va dau
dan de » dan den, dang de, van de
de cua » le cua, te cua, dieu cua
va cao » va cac, va dao, va bao
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: ((thuoc sach) or (thuat sach)) v nang x hoi. hieu ((va cao) OR (va co)) tuc 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 x hoi. hieu ((va cao) OR (va co)) tuc 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 x hoi. hieu ((va cao) OR (va co)) tuc va dan de cua tre".
• Adding a wildcard symbol may retrieve word variants: ((thuoc sach) or (thuat sach)) v nang x hoi. hieu ((va cao) OR (va co)) tuc va dan de cua tre*.