Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
hieu van » hieu va, thien van, lieu va
van cham » van chat, van tham, va cham
cham luc » cham soc, nhan luc, cham cuu
va thanh » gia thanh, va tinh, le thanh
cuu tre » cua tre, cau tren, cau treo
vi cuu » vi luu, vinh cuu
o hoi » co hoi, o hoc, o hai

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu cac ky nang ((o hoi) or (x ho)). hieu van cham luc ((va thanh) OR (ban thanh)) vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu cac ky nang ((o hoi) OR (x ho)). hieu van cham luc ((va thanh) OR (ban thanh)) vi cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu cac ky nang ((o hoi) or (x ho)). hieu van cham luc ((va thanh) OR (ban thanh)) vi cuu tre".
• Adding a wildcard symbol may retrieve word variants: tu cac ky nang ((o hoi) or (x ho)). hieu van cham luc ((va thanh) OR (ban thanh)) vi cuu tre*.