Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
va nang » van nang, da nang, cam nang
ly nang » ky nang, ly hang, ly vang
hieu va » lieu va, hieu qua
cac duc » cac du, cao duc, cac dac
va hanh » van hanh, va thanh, va danh
hanh le » thanh le, hanh ve, hanh de
le cua » ly 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: ((te sach) or (toc sach)) ((va nang) or (ly nang)) x hoi. hieu va cac duc va hanh le cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ((va nang) OR (ly nang)) x hoi. hieu va cac duc va hanh le cua vat.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ((va nang) or (ly nang)) x hoi. hieu va cac duc va hanh le cua vat*.