Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
toc sach » hoc sach, doc sach, nuoc sach
hanh de » hanh ve, hanh kem
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
nang xa » nang x, lang xa, nang ma
vu nang » vuc nang, va nang, vu dang
luc va » duc va, loc va
tuc va » thuc va, truc va, tuc xa
de cua » le cua, te cua, dieu cua
va cam » va cham, va cac, va cao

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

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