Perhaps you should try some spelling variations:
vu khach » vu khanh, vu khac, vay khach
hieu van » hieu va, thien van, lieu va
cua viet » ca viet, hoa viet, cua vat
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va
va hanh » van hanh, va thanh, va danh
y nang » ky nang, ly nang, v nang
soc va » hoc va, loc va, doc va
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: ((tu sach) or (vu khach)) y nang xa hoi. ((hieu ve) OR (hieu van)) cham soc va hanh vi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (vu khach)) y nang xa hoi. ((hieu ve) OR (hieu van)) cham soc va hanh vi cua viet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (vu khach)) y nang xa hoi. ((hieu ve) OR (hieu van)) cham soc va hanh vi cua viet*".