Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
van nhan » van phan, van thanh, danh nhan
nhan luc » nang luc
cao hoi » cau hoi, co hoi, cao hoc
cho hoc » co hoc, khoa hoc
van anh » van thanh, tuan anh
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v 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 y nang ((cao hoi) or (cho hoc)). hieu van nhan luc ((van anh) OR (van minh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y nang ((cao hoi) OR (cho hoc)). hieu van nhan luc ((van anh) OR (van minh)) vi cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y nang ((cao hoi) or (cho hoc)). hieu van nhan luc ((van anh) OR (van minh)) vi cua tre*".