Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
danh dau » lanh dao, hang dau, danh tu
van chat » cao chat
hieu van » hieu va, thien van, lieu va
sach ky » sac ky, sach y, sach ty
nang xa » lang xa, nang ma, mang xa
dau cua » dai cua, day cua, cau cua
tu sach » thu sach, su sach, te sach
soc va » hoc va, loc va, goc va
doc va » duoc va, hoc va, duc va

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