Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van chat » cao chat
dinh dai » dinh dat, sinh dai, dinh dao
cua viet » ca viet, hoa viet, cua vat
sach ky » sach y, sach ty, sach kem
nang xa » nang x, lang xa, nang ma
sac ky » cac ky, sai ky
doc va » duoc va, duc va, loc 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) or (sac ky)) nang xa hoi. hieu van chat ((hoc va) or (doc va)) dinh dai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sac ky)) nang xa hoi. hieu van chat ((hoc va) OR (doc va)) dinh dai cua viet.
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sac ky)) nang xa hoi. hieu van chat ((hoc va) or (doc va)) dinh dai cua viet*.