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, cua vat, cua dieu
tu sach » su sach, te sach, tu cach
nang xa » nang x, lang xa, nang ma
cua coc » cua cac, cua co, cua hoc
y nang » ky nang, ly nang, v nang
luc ca » luc cao, luc cua, luc va
ca dan » cac dan, ca dao
dan va » doan va, dan ca, ban va

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 ca dan va ((cua viet) OR (hoa viet))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thu sach)) y nang xa hoi. hieu cua coc luc ca dan va ((cua viet) OR (hoa viet))~".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) y nang xa hoi. hieu cua coc luc ca dan va ((cua viet) OR (hoa viet))*.