Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu cua » hieu qua, dieu cua, bieu cua
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
nang xa » nang x, lang xa, nang ma
cac luc » cau luc, coc luc, cac cuoc
ca viet » va viet, co viet, hoa viet
y nang » ky nang, ly nang, v nang
va dan » ca dan, va dao, va dau
dan va » doan va, dan ca, ban va
va ca » va cac, va cao, va cai

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

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