Perhaps you should try some spelling variations:
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
thanh de » hanh de, thanh ve, thanh le
thanh do » thanh pho, thanh hoa, thanh loi
dang xay » dang van, van xay
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
cuu tre » cua tre, cau tren, cau treo

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky ((nang xa) or (dang xay)) hoi. hieu va cac nuoc va ((thanh do) OR (thanh de)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((nang xa) OR (dang xay)) hoi. hieu va cac nuoc va ((thanh do) OR (thanh de)) cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky ((nang xa) or (dang xay)) hoi. hieu va cac nuoc va ((thanh do) OR (thanh de)) cuu tre".
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang xa) or (dang xay)) hoi. hieu va cac nuoc va ((thanh do) OR (thanh de)) cuu tre*.