Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
hieu cua » hieu qua, dieu cua, bieu cua
cua viet » ca viet, hoa viet, cua vat
tu sach » su sach, te sach, tu cach
nang xa » nang x, lang xa, nang ma
cua coc » cua cac, cua co, cua hoc
luc cac » luoc cac, tuc cac, duc cac
y nang » ky nang, ly nang, v nang
dan va » doan va, dan ca, ban va
va cua » va chua, via cua, ca cua

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) y nang xa hoi. hieu cua coc luc cac dan va cua viet~.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) y nang xa hoi. hieu cua coc luc cac dan va cua viet*.