Perhaps you should try some spelling variations:
sach thue » sach thieu, sach tham, cach thuc
nhan luc » nang luc
sach thu » sach thieu, sach tham, cach thuc
va nhan » van nhan, ca nhan, va phan
tai cua » thai cua, tai cuc, tri cua
han tai » hang tai, nhan tai, van tai
hieu va » lieu va, hieu qua
va han » va phan, van han, va hanh
luc va » duc va, tuc va, loc va
co hoi » co hoc, co loi
cua tu » cua tuc, cua su, cua cu
o hoi » o hoc, o hai, o hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: te ((sach thu) OR (sach thue)) nang ((o hoi) or (co hoi)). hieu va nhan luc va han tai cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach thu) OR (sach thue)) nang ((o hoi) OR (co hoi)). hieu va nhan luc va han tai cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach thu) OR (sach thue)) nang ((o hoi) or (co hoi)). hieu va nhan luc va han tai cua tu".
• Adding a wildcard symbol may retrieve word variants: te ((sach thu) OR (sach thue)) nang ((o hoi) or (co hoi)). hieu va nhan luc va han tai cua tu*.