Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
nhan duc » nhan duoc, nhan luc, phan duc
sach ky » sac ky, sach y, sach ty
hieu va » hieu qua
va dan » ca dan, va dao, va dau
ca hoa » cau hoa, cam hoa, cai hoa
x hoi » xa hoi, x ho, 5 hoi
o hoi » co hoi, o hoc, o hai

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 ky nang ((x hoi) or (o hoi)). ((hieu va) or (lieu va)) nhan duc va dan ca hoa viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang ((x hoi) OR (o hoi)). ((hieu va) OR (lieu va)) nhan duc va dan ca hoa viet.
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang ((x hoi) or (o hoi)). ((hieu va) or (lieu va)) nhan duc va dan ca hoa viet*.