Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
va triet » va thiet, va trien, ve triet
nhan luc » nang luc
qua nhan » cua nhan, qua nhat, qua phan
sach ky » sac ky, sach ty, sach kem
luc van » luoc van, luu van, duc van
nang o » nang co, nang ho, nang ro
ban vi » ban voi, ban va, ban ve
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 ((sach ky) or (sach y)) nang o hoi. hieu qua nhan luc van ban vi ((va triet) or (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sach y)) nang o hoi. hieu qua nhan luc van ban vi ((va triet) OR (su triet)).
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sach y)) nang o hoi. hieu qua nhan luc van ban vi ((va triet) or (su triet))*.