Perhaps you should try some spelling variations:
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
hieu va » hieu qua
lang vi » hang vi, lang va, sang vi
va lang » va nang, hoa lang
su sach » so sach, vu sach
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
cua tre » cua te, cuu tre, cua triet
sach v » sach va, sach y, sach 2
vi cua » vai cua, di cua

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