Perhaps you should try some spelling variations:
nuoc sach » nguoi sach, hoc sach, cuoc cach
doc sach » hoc sach, toc sach, dac sac
van hanh » van thanh, ban hanh, van anh
cham luc » cham soc, nhan luc, cham cuu
va hanh » va thanh, va danh, ban hanh
va cham » va chat, va tham
hieu va » lieu va, hieu qua
va nang » van nang, da nang, cam nang
cua tre » cua te, cuu tre, cua triet
di cua » dai cua, doi cua, de 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: ((nuoc sach) or (doc sach)) va nang x hoi. hieu va cham luc ((va hanh) OR (van hanh)) di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((nuoc sach) OR (doc sach)) va nang x hoi. hieu va cham luc ((va hanh) OR (van hanh)) di cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((nuoc sach) or (doc sach)) va nang x hoi. hieu va cham luc ((va hanh) OR (van hanh)) di cua tre*".