Perhaps you should try some spelling variations:
doanh than » doanh thanh, doanh nhan, doanh phan
nang mai » nang ma, nang tai, lang mai
so triet » su triet, so thiet, bo triet
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
mai hoi » mai khoi, dai hoi, lai hoi
va chat » van chat, va phat, cao chat
than so » than sao, than vo, than go
xuc va » tuc va, luc va, xac va

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 ky nang mai hoi. lieu va chat ((xuc va) or (duc va)) doanh than so triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang mai hoi. lieu va chat ((xuc va) OR (duc va)) doanh than so triet.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang mai hoi. lieu va chat ((xuc va) or (duc va)) doanh than so triet*.