Perhaps you should try some spelling variations:
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
tu sach » thu sach, te sach, tu cach
su sach » so sach, vu sach
nang xa » lang xa, nang ma, mang xa
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
va dau » va dao
dau de » dau ve, dai de, sau de
de cua » le cua, te cua, dieu cua

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 ((nang xa) or (nang x)) hoi. hieu va cac nuoc va dau de cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky ((nang xa) OR (nang x)) hoi. hieu va cac nuoc va dau de cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (su sach)) ky ((nang xa) or (nang x)) hoi. hieu va cac nuoc va dau de cua tre*".