Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
van hanh » van thanh, ban hanh, van anh
cac vung » cac ung, cac chung, cach dung
cac vuc » cac nuoc, cac cuoc, cac quoc
cua cau » cua cac, cua chu, cua cay
hieu ve » hieu va, hieu van
cho hoc » co hoc, khoa hoc
ty nang » ky nang, ty hang, ly nang
vi cua » vai cua, di 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 xang)) cho hoc. hieu ve ((cac vuc) or (cac vung)) van hanh vi cua cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((ty nang) OR (ty xang)) cho hoc. hieu ve ((cac vuc) OR (cac vung)) van hanh vi cua cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((ty nang) OR (ty xang)) cho hoc. hieu ve ((cac vuc) or (cac vung)) van hanh vi cua cau*".