Perhaps you should try some spelling variations:
doc sach » toc sach, nuoc sach, dac sac
hoc sach » hoc sinh, hoc cac, hoc anh
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
hanh tai » thanh tai, hang tai, han tai
va hanh » van hanh, va thanh, va danh
tai cua » thai cua, tai cuc, tri cua
cua tre » cua te, cuu tre, cua triet
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: ((doc sach) or (hoc sach)) ky nang x hoi. lieu va cac nuoc va hanh tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doc sach) OR (hoc sach)) ky nang x hoi. lieu va cac nuoc va hanh tai cua tre.
• Adding a wildcard symbol may retrieve word variants: ((doc sach) or (hoc sach)) ky nang x hoi. lieu va cac nuoc va hanh tai cua tre*.