Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
dang xay » dang van
hieu van » thien van, lieu va, hieu ve
cham duc » pham duc, cham soc, pham duy
ban hanh » ban hang
hanh hai » thanh hai, nhanh hai, hang hai
hieu va » lieu va, hieu qua
duc ban » duc tan, duc van, dua ban
hai cua » thai cua, dai cua, hoi cua
cua tre » cua te, cuu tre, cua triet

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

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