Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
dai tren » dat tren, dau tren, dan tren
cao hoi » cau hoi, co hoi, cao hoc
hieu ve » hieu va, hieu van
cac tuc » cac tu, cac tac, cac nuoc
cac toc » cac toi, cac nuoc, cac thoi
va hanh » van hanh, va thanh, va danh
y nang » ky nang, ly nang, v nang
vi dai » si dai, li dai, vien dai

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

• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y nang cao hoi. hieu ve ((cac tuc) OR (cac toc)) va hanh vi dai tren~.
• Adding a wildcard symbol may retrieve word variants: thu sach y nang cao hoi. hieu ve ((cac tuc) or (cac toc)) va hanh vi dai tren*.