Perhaps you should try some spelling variations:
hieu sau » hieu su, hieu suat, tieu su
hanh dai » hanh tai, hanh dao, vanh dai
ban hanh » ban hang
chat luc » chat xuc, chat lua, nhan luc
tang tai » hang tai, dung tai, sang tao
sau chat » sat chat, sau chan, soat chat
luc ban » duc ban, cuc ban, luc bat
tu sach » thu sach, su sach, tu cach
tai hoi » tai khoi, dai hoi, tai hai
ky tang » ky nang, ky dang, kho tang
te sach » toc sach
cua te » cua tu
cua su » qua su

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 (te sach)) ky tang tai hoi. hieu sau chat luc ban hanh dai ((cua te) or (cua su))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) ky tang tai hoi. hieu sau chat luc ban hanh dai ((cua te) OR (cua su)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (te sach)) ky tang tai hoi. hieu sau chat luc ban hanh dai ((cua te) or (cua su))".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (te sach)) ky tang tai hoi. hieu sau chat luc ban hanh dai ((cua te) or (cua su))*.