Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
doanh cua » doanh luan
chua tre » chua tri, cua tre, chua trieu
cua chua » sua chua, cua chu, cua nhua
va doanh » van doanh, vay doanh, va danh
cham loc » cham soc, chon loc, cham o
hieu so » thieu so
tu sach » thu sach, su sach, te sach
hieu vu » hieu va, hieu ve, hieu su
sang ma » tang ma, nang ma, sang tao
ky sang » ky nang, ky dang, ky tang
ma hoi » mai hoi, xa hoi, ma hoa
loc va » hoc va, luc 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) or (thuoc sach)) ky sang ma hoi. ((hieu vu) or (hieu so)) cham loc va doanh cua chua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thuoc sach)) ky sang ma hoi. ((hieu vu) OR (hieu so)) cham loc va doanh cua chua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thuoc sach)) ky sang ma hoi. ((hieu vu) or (hieu so)) cham loc va doanh cua chua tre*.