Perhaps you should try some spelling variations:
tham thuoc » pham thuoc, tham thuc, nha thuoc
thuoc ban » thuoc tan, thuoc dang, thu ban
cua viet » ca viet, hoa viet, cua vat
hanh vai » hanh vi, hanh va, hanh tai
ban hanh » ban hang
dang may » mang may, dang xay, dung may
vai cua » dai cua, hai cua, lai cua
hieu va » hieu qua
may hoi » may thoi, tay hoi, mai hoi
ky dang » ky nang, ky danh
tu sach » thu sach, su sach, te sach
tu sac » tu cac, tu san, tu bac

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sac) OR (tu sach)) ky dang may hoi. ((hieu va) or (lieu va)) tham thuoc ban hanh vai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sac) OR (tu sach)) ky dang may hoi. ((hieu va) OR (lieu va)) tham thuoc ban hanh vai cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sac) OR (tu sach)) ky dang may hoi. ((hieu va) or (lieu va)) tham thuoc ban hanh vai cua viet".
• Adding a wildcard symbol may retrieve word variants: ((tu sac) OR (tu sach)) ky dang may hoi. ((hieu va) or (lieu va)) tham thuoc ban hanh vai cua viet*.