Perhaps you should try some spelling variations:
thieu vien » thieu nien, thieu bien, thu vien
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
dang xay » dang van, van xay
vien cac » vien bach, vien dai, vien da
va hanh » van hanh, va thanh, ban hanh
va danh » va dinh, va dan, dia danh
tu sach » thu sach, te sach, tu cach
xay hoi » xa hoi, tay hoi, cay phoi
ky dang » ky nang, ky danh
su sach » so sach, vu sach
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (su sach)) ky dang xay hoi. thieu vien cac nuoc ((va danh) or (va hanh)) dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky dang xay hoi. thieu vien cac nuoc ((va danh) OR (va hanh)) dai cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) ky dang xay hoi. thieu vien cac nuoc ((va danh) or (va hanh)) dai cua tre*.