Perhaps you should try some spelling variations:
thuoc van » thuoc va, thuc van, thuoc ban
nam thuoc » nam thuc, nam thu, nha thuoc
van doanh » toan doanh, van dong, van thanh
doanh va » doan va, doanh tai, doanh cua
tu sach » thu sach, te sach, tu cach
su sach » so sach, vu sach
cao hoi » cau hoi, co hoi, cao hoc
hieu va » lieu va, hieu qua
huu tre » huu tri, cuu tre, huu them
y nang » ky nang, ly nang, v nang
va nam » van nam, ha nam, va nay
va huu » vu huu

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 (su sach)) y nang cao hoi. hieu va nam thuoc van doanh va huu tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (su sach)) y nang cao hoi. hieu va nam thuoc van doanh va huu tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (su sach)) y nang cao hoi. hieu va nam thuoc van doanh va huu tre*.