Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
nhan luc » nang luc
chat hoc » chat hoa, chat thom, cho hoc
van anh » van thanh, tuan anh, van minh
nam luc » nang luc, nam thuc, nam duoc
sach ly » sach y, sach lo, sach ty
ly nang » ky nang, ly hang, ly vang
cua tre » cua te, cuu tre, cua triet
anh vi » hanh vi, anh va, anh ve
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 ly nang ((cau hoi) or (chat hoc)). hieu van ((nam luc) or (nhan luc)) van anh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ly nang ((cau hoi) OR (chat hoc)). hieu van ((nam luc) OR (nhan luc)) van anh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach ly nang ((cau hoi) or (chat hoc)). hieu van ((nam luc) or (nhan luc)) van anh vi cua tre*.