Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
xay danh » day danh, vay doanh, xay dung
dai danh » dai dang, dao danh, day danh
sach ky » sac ky, sach y, sach ty
cao hoi » cau hoi, co hoi, cao hoc
ban cua » ban quan
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 nang cao hoi. hieu van nam thuc ((xay danh) or (dai danh)) ban cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky nang cao hoi. hieu van nam thuc ((xay danh) OR (dai danh)) ban cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach ky nang cao hoi. hieu van nam thuc ((xay danh) or (dai danh)) ban cua tre*.