Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
danh hai » dang hai, lanh hai, manh hai
ban danh » ban doanh, ban hanh, ban dan
manh xay » nganh xay, van xay, dang xay
hieu va » lieu va, hieu qua
hai cua » thai cua, dai cua, hoi cua
duc ban » duc tan, duc van, dua ban
cac duc » cac du, cao duc, cac dac
hieu ve » hieu van
sach ky » sac ky, sach y, sach ty
anh xay » anh hay, nganh xay, dang xay
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: toc sach ky ((anh xay) OR (manh xay)) hoi. ((hieu ve) or (hieu va)) cac duc ban danh hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky ((anh xay) OR (manh xay)) hoi. ((hieu ve) OR (hieu va)) cac duc ban danh hai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky ((anh xay) OR (manh xay)) hoi. ((hieu ve) or (hieu va)) cac duc ban danh hai cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ky ((anh xay) OR (manh xay)) hoi. ((hieu ve) or (hieu va)) cac duc ban danh hai cua tre*.