Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van chat » cao chat
danh dau » lanh dao, hang dau, danh tu
cua viet » ca viet, hoa viet, cua vat
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
dau cua » dai cua, day cua, cau cua
y nang » ky nang, ly nang, v nang
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 y nang xa 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 y nang xa hoi. hieu van chat ((soc va) OR (doc va)) danh dau cua viet*.