Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van chat » cao chat
danh cau » danh dau, danh ca, danh hau
cua viet » ca viet, hoa viet, cua vat
tu sach » thu sach, su sach, te sach
cau cua » cau qua, ca cua, cu cua
y nang » ly nang, v nang, may 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) OR (ky nang)) xa hoi. hieu van chat ((soc va) or (doc va)) danh cau cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((y nang) OR (ky nang)) xa hoi. hieu van chat ((soc va) OR (doc va)) danh cau cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((y nang) OR (ky nang)) xa hoi. hieu van chat ((soc va) or (doc va)) danh cau cua viet".
• Adding a wildcard symbol may retrieve word variants: tu sach ((y nang) OR (ky nang)) xa hoi. hieu van chat ((soc va) or (doc va)) danh cau cua viet*.