Perhaps you should try some spelling variations:
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
doanh co » doanh cua, doanh va, anh co
tu sach » thu sach, su sach, te sach
danh co » danh cho, anh co, danh ca
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
nang xa » lang xa, nang ma, mang xa
ve cac » va cac, vien cac

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 ky ((nang xa) or (nang x)) hoi. hieu ve cac nuoc va ((danh co) OR (doanh co)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang xa) OR (nang x)) hoi. hieu ve cac nuoc va ((danh co) OR (doanh co)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((nang xa) or (nang x)) hoi. hieu ve cac nuoc va ((danh co) OR (doanh co)) cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang xa) or (nang x)) hoi. hieu ve cac nuoc va ((danh co) OR (doanh co)) cua tre*.