Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
van hanh » van thanh, ban hanh, van ban
van anh » van thanh, tuan anh, van minh
hieu ve » hieu va, hieu van
ty hang » ly hang, ty xang, thi hang
ty nang » ky nang, ty xang, ly nang
cua tre » cua te, cuu tre, cua triet
ve cau » ke cau, va cau, ve cac
le cua » ly cua

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 ((ty nang) or (ty hang)) xa hoi. hieu ve cau truc ((van hanh) or (van anh)) le cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((ty nang) OR (ty hang)) xa hoi. hieu ve cau truc ((van hanh) OR (van anh)) le cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach ((ty nang) or (ty hang)) xa hoi. hieu ve cau truc ((van hanh) or (van anh)) le cua tre*.