Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
van hang » van khang, van hoang, van thang
nhan luc » nang luc
cham luc » cham soc, cham cuu, chat lua
hang ly » huong ly
hieu ve » hieu va, hieu van
mai hoi » mai khoi, dai hoi, lai hoi
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
ma hoi » xa hoi, ma hoa, me hoi
ly cua » le 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 ((ma hoi) or (mai hoi)). hieu ve ((cham luc) OR (nhan luc)) van hang ly cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y nang ((ma hoi) OR (mai hoi)). hieu ve ((cham luc) OR (nhan luc)) van hang ly cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y nang ((ma hoi) or (mai hoi)). hieu ve ((cham luc) OR (nhan luc)) van hang ly cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach y nang ((ma hoi) or (mai hoi)). hieu ve ((cham luc) OR (nhan luc)) van hang ly cua tre*.